On Wed, 22 Nov 2017 22:00:01 +0000, (Roger Hayter)
wrote:
snip

No, you may well be right but that might at least open up a trading
standards question?


It would have to be an unequivocally false statement rather than simply
marketing hype for a business customer to have a valid complaint.

Sure, I'm not saying it would be black and white etc.

After all, they probably do provide 2kW in the open air at -10degC.

They also provide 2kW for around two hours in a room that is around
(if I remember correctly) sub 16 DegC.

dave also reported that the surface temperature of the radiator was
about 98 DegC so that is quite a differential?

Cheers, T i m

T i m wrote:

On Wed, 22 Nov 2017 22:00:01 +0000, (Roger Hayter)
wrote:
snip

No, you may well be right but that might at least open up a trading
standards question?


It would have to be an unequivocally false statement rather than simply
marketing hype for a business customer to have a valid complaint.

Sure, I'm not saying it would be black and white etc.

After all, they probably do provide 2kW in the open air at -10degC.

They also provide 2kW for around two hours in a room that is around
(if I remember correctly) sub 16 DegC.

dave also reported that the surface temperature of the radiator was
about 98 DegC so that is quite a differential?

Cheers, T i m

Yes, but for a business to business transaction I reckon that falls
under caveat emptor. A consumer might have a pretty hard task proving
it wasn't accurately described to a small claims court, but I don't
think Trading Standards would be very interested even then. It might
help if anyone knows how common such limited heat convection is among
competing products.

--

Roger Hayter

On Wed, 22 Nov 2017 23:04:55 +0000, (Roger Hayter)
wrote:

T i m wrote:

On Wed, 22 Nov 2017 22:00:01 +0000, (Roger Hayter)
wrote:
snip

No, you may well be right but that might at least open up a trading
standards question?


It would have to be an unequivocally false statement rather than simply
marketing hype for a business customer to have a valid complaint.

Sure, I'm not saying it would be black and white etc.

After all, they probably do provide 2kW in the open air at -10degC.

They also provide 2kW for around two hours in a room that is around
(if I remember correctly) sub 16 DegC.

dave also reported that the surface temperature of the radiator was
about 98 DegC so that is quite a differential?

Cheers, T i m

Yes, but for a business to business transaction I reckon that falls
under caveat emptor.

Really, even for something like that that *could* be a safety issue?

A consumer might have a pretty hard task proving
it wasn't accurately described to a small claims court, but I don't
think Trading Standards would be very interested even then.

But if a 2kW heater doesn't give off 2kW under 'typical' conditions,
is it 'of merchantable quality'? (or whatever the terms are)?

It might
help if anyone knows how common such limited heat convection is among
competing products.

It would indeed.

Cheers, T i m

On Wednesday, 22 November 2017 18:35:18 UTC, T i m wrote:
On Wed, 22 Nov 2017 09:08:47 -0800 (PST), whisky-dave
wrote:

snip

Well we wouldn't have contacted sales as they'd just say send it back irrespective of the problem whether there was one or not.

Are you intent on being difficult on everything, even when people are
trying to help you?

Telling me to send the items back

I told you to do no such thing. I suggested they may be faulty and you
might raise the issue with the supplier and / or the manufacturer.

Which is what I have done after being able to check all 5 of teh 5 we were given.


when I don't believe anything is worng

What you *believe* is irrelevant

No it isn't, if I believe something is dangerous I need to take it out of action so thinking is important.

(especially considering how many
people have put so much effort into trying to *help* you / understand)
and you were the one raising the whole issue here in the first place
etc, *especially* why it was cutting from 1600 to 700, not zero watts.

Yes take a look at the original subject line.



isn;t helpful

I think it's all over the top helpful and I suggest 'most people'
would agree.

you me you.

So answer the original Q


and then we'd have to close the lab resulting in delayed corses and a back log.

Irrelevant. That's possibly like leaving the same insulation tiles on
other buildings like Grenfell because it will make them colder.

Nothing like that at all.


I have also delt with CPC before, when I asked them why their extractor fans at about ~£28 were so much cheaper than the farnell versions about ~£42 or so.

That's a sales, not a safety issue.



They said it was because CPC didn't supply any technical details or any help.

shrug See how much help they 'don't give' if you suggest there could
be a safety issue and therefore a potential threat to life.

which I can only do after I have checked them all.


I asked them a question without buying the product in question myself
and they replied pretty quickly and willing to take it further?

I sent my email this morning as I have now checked them.


Tested all 5 heaters and they apparently all have exactly the same 'problem' or 'fault' which to me seems unlikely.

There you go again with you blinkers and denial.

It's not denial I'm the one testing these things out, who else has done this.


"When you have eliminated the impossible, whatever remains, however
improbable, must be the truth".

Yes sherlock.

But I hadn't eliminated the impossible.



I would contact tech support using their on-line form.

And I emailed them using the link for tech support and not expecting
any thanks (luckily).

what link ?

http://cpc.farnell.com/contact-us

there is NO tech suport email link.

What? Are you blind or just trolling?

"Technical Support
Email: "

*That* is the link given for emailing tech support, that's why I used
it! Maybe it confuses you that it isn't
?

Well I used as that's what the link I clicked on went to rather than sales.

http://cpc.farnell.com/contact-us

Technical Support

Online Query Form: Log a Technical Query
Email:
Telephone: 03447 880088
Fax: NA
Opening Times: 08:00-19:00, Monday - Friday. 09:00-17:00, Saturday


for some strange reason yuo say yuo used the email address for sales where as I clicked on the link Log a Technical Query, which is what I have.

I want to know what consumption a 2KW heater should consume, as indicated by the subject line from teh very first post.



"Our technical team have advised that they believed this to be faulty"

Yes believe....

Of course, they haven't had them beck to test them themselves have
they?

Well they have 346 in stock.

OK.

No sign of them withdrawing them as yet.

I'm guessing they haven't had your order number to check that the
person asking for the technical advice has actually bought such from
them etc yet?

quite likely as another form you have to type in yuor account number which I dontl have or rathe rthey weren;t ordered via 'my' account, which is why I was looking for an alternative option other than sales who rarely now technical details but are good at stock levels and pricing and teh like, perhaps this is why they have differnt email addresses


The bigger issue is if we are talking a one off or the whole batch
here.

Yes I know, but at least one of them has been passed by our electrical tester bloke so it must be safe to use.

Are you just trolling again?

No stating the facts.

Yes, you are stating 'facts' that are irrelevant to the point.

They seem to be safe to use in the teaching lab as they are, so I'm not worried from a H&S POV.

A std
PAT wouldn't test for a (potential) design fault. (I nearly added
'would it' to the end of that but how would you know)?

If the desgn fault that was a saftly issue the PAT test would show it up.

And another thing the PAT test shows is that this heater was tested in fed 2017 this lable is stuck over the previous label so we've had this since at least feb 2016 and as that one is faulty and teh new ones are faulty this indicates that every heater sold since feb 2016 is faulty and no one else has noticed or reported it.


What sort of 'tests' do you think they
would do that could go any way to justifying your poor understanding
of the entire situation?

The test they legally have to do in order for a product to be considered safe.

Quite. And that test took ~2 hours did it (the time it takes for the
rad to overheat)? They monitored the current for over two hours?

Not sure who they are I would expect this to be done with the prototype.


Just tested the 3rd heater with the same 'problem' or is it a 'feature'.

Ok, so, like I suggested right at the beginning, this could well be a
batch problem.

and it might well not be, but a design feature.

Yes, it *might* not be but we don't know yet do we (other than my
opinion and Tech support at CPC etc)?



And NOW I do have just recieved two emails.

I sent mine at 10:07 this morning.

At 11:14 this morning :-
------------------------------------------
David

This is not how the radiator should work, please contact sales to arrange there return.

Regards
CPC Technical
------------------------------------------

As I was busy switching them off and finding their packaging....

at 11:29 this morning :-
------------------------
David

Unfortunately there was confusion over our initial response, the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat.

We are sorry for any inconvenience caused.

Regards
CPC Technical
-------------------------


________________________________________________

So for me this is now closed and I can re-install the heaters.



Do you have any reason to think it is a batch fault ?

Yes (and I'm not going to explain it yet again).



I'll contact customer services as indicated on the site

As I did you mean?

No you went through sales.

Yes, because that *IS* the (email) path for a 'Technical question'.


Support:
Suggest Feedback / Report A Problem,
Return A Product
Telephone:
03447 11 11 55




after I;'ve tested the 5 x 2KW ones maybe I'll check the smaller 1..6KW too

Ok. So you have two different sizes of heater (as you were going on
about the 2kW only being 1.6kW and you didn't know why).

3 or 4 actually.

Ok.

I did know why they are only 1.6KW.

Not at the beginning you didn't or presumably you wouldn't have asked
here?

Well I wasn't asking why they were 1.6KW but why they were 700W.


"So how much power does an oil filled radiator actually use.
But what really surprised me was the power consumption of a radiator
when it was full on, anyone care to guess what it was."



Support:
Suggest Feedback / Report A Problem,
Return A Product
Telephone:
03447 11 11 55

You don't think there is a problem so why are you reporting one?

you're the one that there's a problem.

Eh?

As I suggested from the evidence of haing a heater that exibited this fault for 2 years so this 'fault'; had been in all these heaters sold over the last 2 years unlikely.


I don't think there is.

But we have already seen just how little you actually understand about
any of this by the amount of time people who do know have spent
correcting and re-explaining it all to you.

But they've all been wrong.


Why is it that you continually insist that you are right and everyone
else is wrong?

Because I believe that is the case with these heaters.

But we should be dealing with science here, not what you happen to
believe.

Which is why I tested them and from the results I got I concluded that rathter than there being a fault they were just cheap heaters, perhaps not up to the spec the datasheet might suggest.


Or is it you just have a strange way of asking a
question?

I wanted to know what someone here might expect to get from a 2KW heater, would they expect 2KW of heat or 700W of heat ?

Sounds like a stupid / trolling question then, especially if you
already knew all the answers?

I only klnew because I tested them whereas you just read the lable on the site.


What would you expect ?

Why do you care, you don't listen to anything else people say?

I will if I think it makes sense, which it hasn't.



"Technical Support
Online Query Form: Log a Technical Query
Email:
Telephone: 03447 880088"


I was asking *if* there was a problem so felt 'Logging a technical
query' was most suitable.

Did you log a technical query', you said sales contacted you.
rememeber.

No, I emailed them a technical question.

emailed who ?

Them was a about ants, pretyy good IIRC well at the time.


How are sales going to know
to contact me (and I don't need to remember what I said, because it is
all fact / truth).

Usually from the email address you use to contact CPC/onecall/farnell



Support:
Suggest Feedback / Report A Problem,
Return A Product
Telephone:
03447 11 11 55



But hey, if you don't approve of the way I was helping you ...

you think that is help ?

And you think your responses to any of the help you have been given
(by me or others here) are appropriate I'm guessing.

yuo contact sales they tell yuo their tech people have said what exaclty..

I posted their reply previously. I'm not your wet nurse.

Where is this tech report ?

It will be in reply to you following up what I started on your behalf
by giving them the order details and / or even suggesting they get one
out of stock (if they haven't already) and prove an issue one way on
another. But you have already explained why nothing is going to happen
so ...

Cheers, T i m

On Wednesday, 22 November 2017 20:02:36 UTC, John Rumm wrote:
On 22/11/2017 12:36, whisky-dave wrote:
On Tuesday, 21 November 2017 20:13:50 UTC, John Rumm wrote:
On 21/11/2017 11:29, whisky-dave wrote:
On Monday, 20 November 2017 19:03:54 UTC, John Rumm wrote:

Its much the same situation with a fuse. Both will permit
small overloads for a long duration. In some cases (much
depending on the installation method used for the cable) even
that may result in cable damage, or at the very least premature
ageing.

Yes I know, but what I don't know is whether a 32A MCB would be
used with cable that the MCB is not up to protecting.

For a general purpose ring circuit,


I'm not sure if that is the case, we are an electronics teaching
lab.

If it has a ring, and lots of sockets into which you can plug any device
you fancy, then its classed as a general purpose circuit.

fine.


(a non general purpose socket would be circuits for individual bits of
kit, like an immersion heater circuit or a fire alarm one - i.e.
situations where you know all about the specific equipment/load at
design time)

How about 'cleaners' sockets that don't go through the lab filter ?
or so we have been told which is called the dirty mains.

The only thing you might encounter different is in IT labs where the
large quantities of switched mode PSUs would often require that high
integrity earthing be used as well since there is often quite high earth
leakage when in normal operation as a result of all the input filters /
suppressors.

I'm not sure if 40 or so PCs and dozens of SMPS would count.
But all the lab sockets did have a filter on them.



However the circuit protection would still be the same.

I assume so.



I would assume this had been checked and done and was even safer than
a home system as we are dealing with students.

If working correctly then it should be on par with that done in domestic
situations.

Me too.


Commercial installs often tend to make use of larger numbers of radial
circuits with smaller MCBs - usually just to provide better
discrimination in the event of a fault, and the ability to isolate
smaller sections of the infrastructure.

which is why we have our benches split into seprate rings and 2 phases.



Well here;s a link to our riser.
https://www.dropbox.com/s/u1rnoxretw..._0844.JPG?dl=0

the box opened is the one in the centre of the riser

https://www.dropbox.com/s/jr39axmtv0..._0845.JPG?dl=0

If that tells you anything.

Yup, normal memshield2 commercial style 3 phase CU. Which "room" is yours?

251 PC lab, 252 Now the PCB room (this year),
253 the hardware lab (my lab), 254 my office, 255 ex power lab with 3 phase installed.



However, some interesting things to note the

Many of those MCBs are not actually MCBs but RCBOs - i.e. they include
RCD and MCB functionality in one unit (this is good for a situation like
yours since any earth leakage faults will only take out the affected
circuit and not others). Although this does mean that when seeing a
trip, you need to decide if its an over-current one or an earth leakage
one.

Yes, but they have sfor the last 15 years+ just been refered to as MCBs.
Previuosly these were RCD and that;'s what they were called in the days when it was my job to test them. Then that all changed with the £30K upgrade to the labs electrics.
I was then told NOT to test them and that if they tripped we'd need to call the 'estates team' in to come and sort any problem out.
Which I must admit we tend to ignore, unless of course something really serious happens.




(I don't know if the memshield2 RCBOs have a different "RCD tripped"
dolly position from the normal overcurrent tripped one - Adam might know?).

me niether AFAIK I shouldn't even be opening the box.


The other interesting thing is that most of those socket circuits are
protected by C type devices. That means that the fault current required
to open one is double that which we have been discussing! However the
good news is that only applies to Live to Neutral faults and not Live to
Earth faults since the RCD part of the RCBO will take care of those at
=30mA.

Yes I thought it was something like that and this is also more likely to happen when dealing with students. Than a short between live & Neutral.



Yes I know I buy then, Quick blow, anti surge, time delay,
semi-delay, 'normal' I'm just glad I don't have to worry about
male and female and LGBTQ versions. Don't seem to nhave those
options with MCBs

You have a similar choice (at least for the larger loads): Common
nominal ratings of 3, 6, 10, 16, 20, 32, 40, 45, 50, 63 (and
possibly others depending on range and brand)

Three different fault / inrush characteristics: Types B, C, & D

And often a range of maximum breaking currents, typically 6kA, and
10KA, but again there are others. (those plug in wylex 3036
rewireable replacements often only do 3kA)

The memshield2 breakers are often 10kA rated BTW - so higher breaking
capacity than most domestic stuff.

I wonder why, I'd have thought the cable would have vapourised long before 10kA .


I would assume that the installers that charged us £30k last
renovation had the sorted.

You know what they say about assumptions!

That they are like arse holes ?


(to be fair, the kit they have used is decent stuff)

That's nice to know, so thanks for that info.


Is there any likelihood that your combination of loads will
have exceeded 100A?

No, we no longer have a power lab, labs here. well they are all
done on the ELVIS system now or which we have about 30 in use.
http://www.ni.com/en-gb/shop/select/...ab-workstation


Yup, cute, but not really "power electrics" is it? ;-)

Yes it is for teaching purposes we run a course on it and it's the
standard kit for teaching power at degree level anyway.


(I recall an ex Marconi college engineer lamenting the lack of
exposure to things over 5V by most of the current generation of new
engineers - he used to like demoing drawing an arc a couple of
metres long from the output of a high power transmitter!)

5V ! we're trying to keep them to 3.3V. ;-)

Mmmm smell the ozone, feel the hairs on your arms perk up in the
electric field!

:-D
Yesterday an IoT (internet of Things) student asked for a 5V battery, when I said I don't have any he asked "well how am I supposed to work on my project at home then"


If your fault current is not high enough to trip the magnetic
response of the MCB,

What current is that then ? Is 32 amp OK and 33 a fault. ?

For a B32 MCB the minimum fault current to be *sure* of getting an
instant trip would be the 5x In rating, or 160A

Given your pictures above, make that 320A... however:

I've always thought that fault tripping was meant to go at 30ma or
less when there was an inbalance between of curretn detected in the
earth.

With a RCD or RCBO yes. Since you have RCBOs on the socket circuits,
then faults to earth will be cleared even if the circuits don't meet the
maximum allowed earth loop impedance.

That makes the whole situation less worrying, since the only fault that
won't be cleared is the less common L to N fault. (although given the
type C device there is probably no chance of clearing such a fault on
the instant part of the trip if you ever did get one of those)


So it looks like what's been installed is what's needed in the lab and up to standard so everythings OK.


Its the one in the table on the RHS of the graph:

http://wiki.diyfaq.org.uk/images/d/d...e-MCBTypeB.png

I wonder if 160A going through a student would cause any damage or
would it even be noticable, woul,d oit wake them up ?

To me it seems a bit late to trigger a fault if it takes 160A.

No, that's fine. You don't want it too low, or it would trip with switch
on surges. Remember the magnetic trip facility in the MCB/RCBO is only
there to deal with short circuit style situations, and currents of
hundreds of amps are normally commonplace in these situations.

So as expected everything seems OK.


The thermal part of the trip takes care of the everyday overloads like
someone plugging in a bunch of radiators.

And the RCD trip response will take care of most electrocution risk
events (unless you manage to get a student between L & N while not earthed!)

Looks like I may have to test for that situation :-D


Yes. The "On Site guide" has a table that gives a maximum length
of cable permitted for each of the standard circuit types to save
needing to do the sums. In some cases the limitation is that of
voltage drop, and in others its maximum earth loop impedance. Where
the limitation is the latter, the level is set so that the cable
should always have proper fault protection.

I would hope a teaching lab would come up to those standards.

Pretty much all wiring should.

Since you have RCBOs on each circuit, that generally makes things much
simpler.

Even the students seem simplier ;-)


But the fault curretn is a bit obsure because you;re factoring
in time. What is the fault current of a 32amp MCB.

Nominally 160A for a type B device. 320A for a type C, and 640A for
a D type D.

I would assume that each MCB would be used with the appropriate
cables in place.

Usually yes. (In many cases they could be the same cables).

Threre must be some reason why a B C or D would be
installed.

Yup, B is general purpose and what you see in most domestic installs
(although I usually use type C on lighting circuits to minimise nuisance
trips on filament lamp failures).

That's interesting would the wiring in a typical lighting ring 320A or how about 40A .


Type C is often used with high inrush loads (large transformers,
induction motors, large banks of strip lights etc).

I can imagine strip lights of the flourescant kind needing this, any idea if its true of the recent LED tubes.


Type D is only usually used in industrial settings for things with very
high inrush.

Sounds sexy I wish we had kept some of the old power lab and HV stuff.
I remmeber being told how I'd have to phone up the royal London hospital if we started up our HV lab as it cause interference at the hospital and the generating board needed to be informed in advance.


what happened to A ?

It was left out to avoid any confusion with the current rating of the
device, which would often be specified with "A".

I keep forgeting why in ohms law current is I if a student should ask.

On Thu, 23 Nov 2017 04:19:37 -0800 (PST), whisky-dave
wrote:

snip

Telling me to send the items back

I told you to do no such thing. I suggested they may be faulty and you
might raise the issue with the supplier and / or the manufacturer.

Which is what I have done after being able to check all 5 of teh 5 we were given.

Ok, that's a step in the right direction then.


when I don't believe anything is worng

What you *believe* is irrelevant

No it isn't,

Good.

if I believe something is dangerous I need to take it out of action so thinking is important.

Yes, you do ... and it's not the taking it out of action that should
be the big decision but any delays in *not* taking it out of action.

snip

and then we'd have to close the lab resulting in delayed corses and a back log.

Irrelevant. That's possibly like leaving the same insulation tiles on
other buildings like Grenfell because it will make them colder.

Nothing like that at all.

Everything like that mate. *If* something went wrong and you knew
about a potential issue but failed to do anything about it ...


snip

shrug See how much help they 'don't give' if you suggest there could
be a safety issue and therefore a potential threat to life.

which I can only do after I have checked them all.

Even one faulty one could be an issue ... but 'of course' you could
also rest more and I thought you said you already had (because you
kept denying it was likely to be a batch fault as they all acted the
same)?


I asked them a question without buying the product in question myself
and they replied pretty quickly and willing to take it further?

I sent my email this morning as I have now checked them.

Good.


Tested all 5 heaters and they apparently all have exactly the same 'problem' or 'fault' which to me seems unlikely.

There you go again with you blinkers and denial.

It's not denial

Of course it is as you would have done something sooner rather than
arguing with me why there was no need and why you shouldn't?

I'm the one testing these things out, who else has done this.

You said you had a testing guy come in and do it any you were happy he
found them safe?


"When you have eliminated the impossible, whatever remains, however
improbable, must be the truth".

Yes sherlock.

;-)

But I hadn't eliminated the impossible.

So, what do you know today that you didn't know last week?

snip


for some strange reason yuo say yuo used the email address for sales where as I clicked on the link Log a Technical Query, which is what I have.

You accused me of contacting sales rather than TS. I contacted TS via
the email they offer for TS shrug.

I want to know what consumption a 2KW heater should consume, as indicated by the subject line from teh very first post.

And you didn't know that after measuring it, posting and the fist few
replies?


snip

I'm guessing they haven't had your order number to check that the
person asking for the technical advice has actually bought such from
them etc yet?

quite likely as another form you have to type in yuor account number which I dontl have or rathe rthey weren;t ordered via 'my' account, which is why I was looking for an alternative option other than sales who rarely now technical details but are good at stock levels and pricing and teh like, perhaps this is why they have differnt email addresses

sigh The sales email *is* the contact for TS.


snip

They seem to be safe to use in the teaching lab as they are, so I'm not worried from a H&S POV.

But maybe you should be, until they give you a formal 'all clear' in
any case?

A std
PAT wouldn't test for a (potential) design fault. (I nearly added
'would it' to the end of that but how would you know)?

If the desgn fault that was a saftly issue the PAT test would show it up.

And another thing the PAT test shows is that this heater was tested in fed 2017 this lable is stuck over the previous label so we've had this since at least feb 2016 and as that one is faulty and teh new ones are faulty this indicates that every heater sold since feb 2016 is faulty and no one else has noticed or reported it.

Quite possibly. How many people would plug one into a power meter?


What sort of 'tests' do you think they
would do that could go any way to justifying your poor understanding
of the entire situation?

The test they legally have to do in order for a product to be considered safe.

Quite. And that test took ~2 hours did it (the time it takes for the
rad to overheat)? They monitored the current for over two hours?

Not sure who they are

The guy you think 'tested them'?

I would expect this to be done with the prototype.

Quite and it may have been and then a wiring error crept in ...

snip

Yes, it *might* not be but we don't know yet do we (other than my
opinion and Tech support at CPC etc)?



And NOW I do have just recieved two emails.

I sent mine at 10:07 this morning.

At 11:14 this morning :-
------------------------------------------
David

This is not how the radiator should work, please contact sales to arrange there return.

Regards
CPC Technical
------------------------------------------

As I was busy switching them off and finding their packaging....

at 11:29 this morning :-
------------------------
David

Unfortunately there was confusion over our initial response, the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat.

(Oh, what, with an 'overtemp stat', who would have thought! Lets hope
it still can't overheat when a student forgets they have left their
coat draped over it ...).

We are sorry for any inconvenience caused.

Regards
CPC Technical
-------------------------


_______________________________________________ _

So for me this is now closed and I can re-install the heaters.

Even if that isn't actually the whole story at least you now have
something to cover your back etc.

Now you just need to get them to answer your first question re why
they aren't actually a 2kW heater. ;-)

snip

I did know why they are only 1.6KW.

Not at the beginning you didn't or presumably you wouldn't have asked
here?

Well I wasn't asking why they were 1.6KW but why they were 700W.

Ok.


snip

You don't think there is a problem so why are you reporting one?

you're the one that there's a problem.

Eh?

As I suggested from the evidence of haing a heater that exibited this fault for 2 years so this 'fault'; had been in all these heaters sold over the last 2 years unlikely.

But not impossible (and this is new information to us remember).


I don't think there is.

But we have already seen just how little you actually understand about
any of this by the amount of time people who do know have spent
correcting and re-explaining it all to you.

But they've all been wrong.

Oh really! I'm sure they will love to hear you think that.

snip

Which is why I tested them and from the results I got I concluded that rathter than there being a fault they were just cheap heaters, perhaps not up to the spec the datasheet might suggest.

But in doing said tests you revealed an anomaly that I don't believe
has yet been resolved.

snip

Sounds like a stupid / trolling question then, especially if you
already knew all the answers?

I only klnew because I tested them whereas you just read the lable on the site.

Other than I have tested this exact same thing personally myself?


What would you expect ?

Why do you care, you don't listen to anything else people say?

I will if I think it makes sense, which it hasn't.

And I wonder why that is?

snip

Did you log a technical query', you said sales contacted you.
rememeber.

No, I emailed them a technical question.

emailed who ?

The people they offer for 'Technical questions'?

Them was a about ants, pretyy good IIRC well at the time.

Eh?

Cheers, T i m

On Thursday, 23 November 2017 13:42:32 UTC, T i m wrote:
On Thu, 23 Nov 2017 04:19:37 -0800 (PST), whisky-dave
wrote:

snip

Telling me to send the items back

I told you to do no such thing. I suggested they may be faulty and you
might raise the issue with the supplier and / or the manufacturer.

Which is what I have done after being able to check all 5 of teh 5 we were given.

Ok, that's a step in the right direction then.


when I don't believe anything is worng

What you *believe* is irrelevant

No it isn't,

Good.

if I believe something is dangerous I need to take it out of action so thinking is important.

Yes, you do ... and it's not the taking it out of action that should
be the big decision but any delays in *not* taking it out of action.

snip

I didn't see any delays in NOT taking it out of action only delays in taking it out of action.

and then we'd have to close the lab resulting in delayed corses and a back log.

Irrelevant. That's possibly like leaving the same insulation tiles on
other buildings like Grenfell because it will make them colder.

Nothing like that at all.

Everything like that mate. *If* something went wrong and you knew
about a potential issue but failed to do anything about it ...

But there was NO issue, an imaginged issue perhaps.



shrug See how much help they 'don't give' if you suggest there could
be a safety issue and therefore a potential threat to life.

which I can only do after I have checked them all.

Even one faulty one could be an issue ...

If it were faulty it might be, depending on the fault.


but 'of course' you could
also rest more and I thought you said you already had (because you
kept denying it was likely to be a batch fault as they all acted the
same)?

I did a quick check on 3 of them when I found ONE to be giving 700W when I thought it should be around 1.7KW consumption.
That's why I asked
"So how much power does an oil filled radiator actually use"

I asked them a question without buying the product in question myself
and they replied pretty quickly and willing to take it further?

I sent my email this morning as I have now checked them.

Good.


Tested all 5 heaters and they apparently all have exactly the same 'problem' or 'fault' which to me seems unlikely.

There you go again with you blinkers and denial.

It's not denial

Of course it is as you would have done something sooner rather than
arguing with me why there was no need and why you shouldn't?

I did the right thing it seems.


I'm the one testing these things out, who else has done this.

You said you had a testing guy come in and do it any you were happy he
found them safe?

I was happy with the PAT tester who tests the equipment for electric safety..
Unless equipment has been checked I'm not allowed to use it unless it's new of course.
i.e no sticker do not use.



"When you have eliminated the impossible, whatever remains, however
improbable, must be the truth".

Yes sherlock.

;-)

atually I first heard this from Data on star trek on the holodeck when he was playing sherlock.


But I hadn't eliminated the impossible.

So, what do you know today that you didn't know last week?

That's there's nothing wrong with the heaters and that if the 2KW was used as an indication of teh amount of heat they give off anyone using that in a calculation would get the wrong result if they were trying to calculate how many of these heaters would be required to perform the task of heating.



snip


for some strange reason yuo say yuo used the email address for sales where as I clicked on the link Log a Technical Query, which is what I have.

You accused me of contacting sales rather than TS. I contacted TS via
the email they offer for TS shrug.

yuo must have as you will NOT get technical support unless you enter your account code it's one of the red stared boxes that is compulsury,
* Required, account number and phone number.

I also DID NOT have a working phone both the office phone wa sout of action and so was teh so called emrgency phone.


Unless all those boxes are filled they won't or can't support you.
That is why I couldn't use tech support because I don't have the account code.

http://cpc.farnell.com/technical-support

I had to scroll down and use the Email technical support:

which is the product info email.




Online Query Form: Log a Technical Query
Email:

two seperate email adresses and you told me sales had contected you .






I want to know what consumption a 2KW heater should consume, as indicated by the subject line from teh very first post.

And you didn't know that after measuring it, posting and the fist few
replies?


snip

I'm guessing they haven't had your order number to check that the
person asking for the technical advice has actually bought such from
them etc yet?

quite likely as another form you have to type in yuor account number which I dontl have or rathe rthey weren;t ordered via 'my' account, which is why I was looking for an alternative option other than sales who rarely now technical details but are good at stock levels and pricing and teh like, perhaps this is why they have differnt email addresses

sigh The sales email *is* the contact for TS.


snip

They seem to be safe to use in the teaching lab as they are, so I'm not worried from a H&S POV.

But maybe you should be, until they give you a formal 'all clear' in
any case?

which they have done proving I was right.


A std
PAT wouldn't test for a (potential) design fault. (I nearly added
'would it' to the end of that but how would you know)?

If the desgn fault that was a saftly issue the PAT test would show it up.

And another thing the PAT test shows is that this heater was tested in fed 2017 this lable is stuck over the previous label so we've had this since at least feb 2016 and as that one is faulty and teh new ones are faulty this indicates that every heater sold since feb 2016 is faulty and no one else has noticed or reported it.

Quite possibly. How many people would plug one into a power meter?

same number of people that'd try to set fire to clading to see if it's safe as a building material I suspect.




What sort of 'tests' do you think they
would do that could go any way to justifying your poor understanding
of the entire situation?

The test they legally have to do in order for a product to be considered safe.

Quite. And that test took ~2 hours did it (the time it takes for the
rad to overheat)? They monitored the current for over two hours?

Not sure who they are

The guy you think 'tested them'?

The guy I know tested ONE as that's all I had in feb 2017.
The rest didn't arrive until this month, and as he doesnlt have to test anything that has just been brought he'd most likely check them in feb 2018.




I would expect this to be done with the prototype.

Quite and it may have been and then a wiring error crept in ...

snip

If no one noticed then perhaps it's not an error at all, but a feature.



Yes, it *might* not be but we don't know yet do we (other than my
opinion and Tech support at CPC etc)?



And NOW I do have just recieved two emails.

I sent mine at 10:07 this morning.

At 11:14 this morning :-
------------------------------------------
David

This is not how the radiator should work, please contact sales to arrange there return.

Regards
CPC Technical
------------------------------------------

As I was busy switching them off and finding their packaging....

at 11:29 this morning :-
------------------------
David

Unfortunately there was confusion over our initial response, the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat.

(Oh, what, with an 'overtemp stat', who would have thought! Lets hope
it still can't overheat when a student forgets they have left their
coat draped over it ...).

Well in that case I'd most likely notice as I throw them at at 5pm, this is one reason we've always liked clearing the lab and before the £30k electrical upgrade at 4:45pm every 'night' I used to hit the main power emergency mushroom button switch ALL the electric OFF in the teaching labs in 251 & 253.

Once the students knew there wasn't any power and couldn't find the trace on teh scope and the neons on the PSU had all gone out and when I started switching off the lights the studetns used to leave and there was NO power to the labs.



We are sorry for any inconvenience caused.

Regards
CPC Technical
-------------------------


_______________________________________________ _

So for me this is now closed and I can re-install the heaters.

Even if that isn't actually the whole story at least you now have
something to cover your back etc.

That is my main aim yes, and teh reason I question managment when they told me to leave the heaters on over night when the datasheet/manual says do not leave them unattended.


Now you just need to get them to answer your first question re why
they aren't actually a 2kW heater. ;-)

I know why, 2KW is the maximum at 240V it indicates that on the label.
which is hy I expected less KW with the 23V max we get in the lab and why I wasn;lt too concerned in getting only 1.6KW at 202V


I did know why they are only 1.6KW.

Not at the beginning you didn't or presumably you wouldn't have asked
here?

Well I wasn't asking why they were 1.6KW but why they were 700W.

Ok.


You don't think there is a problem so why are you reporting one?

you're the one that there's a problem.

Eh?

As I suggested from the evidence of haing a heater that exibited this fault for 2 years so this 'fault'; had been in all these heaters sold over the last 2 years unlikely.

But not impossible (and this is new information to us remember).

Is anything impossible watson ;-)

The information was new to me too I'd never run my office heater for long enough to question it's consumption or behavaour.

It was only when I tried to work out why after about an hour why 5x2KW so about 40 amps didn't trip the 32 amp MCB (as I was told to leave them on over night, I wanted to see what would happen during the day)
So I thought to myself maybe the voltage has dropped due to ohms law etc..
So I went to find our power meter which while it worked the batteries were flat, but the reading was 202V, I thought just maybe like some of our meters the battery being flat might have some effect on the reading.
After putting the first heater on teh power meter I got a reading of about 1.6KW, after a few mins it went down to 680W. So like you I thought 'faulty heater', so I tried the next one and that was almost 700W and so was the 3rd.




I don't think there is.

But we have already seen just how little you actually understand about
any of this by the amount of time people who do know have spent
correcting and re-explaining it all to you.

But they've all been wrong.

Oh really! I'm sure they will love to hear you think that.

The heaters are NOT faulty they are design to do that accring to those working for productinfo@CPC.



Which is why I tested them and from the results I got I concluded that rathter than there being a fault they were just cheap heaters, perhaps not up to the spec the datasheet might suggest.

But in doing said tests you revealed an anomaly that I don't believe
has yet been resolved.

For me it has.
"the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat."

what's so hard to understand "an internal thermostat designed to lower the temperature", no mention of any cut-out or thermal fuse or circuit breaker the word trip only appears when talking about tipping the unit over.






snip

Sounds like a stupid / trolling question then, especially if you
already knew all the answers?

I only klnew because I tested them whereas you just read the lable on the site.

Other than I have tested this exact same thing personally myself?

So what were your results ?
Did you send yuor heater back ?


Did you log a technical query', you said sales contacted you.
rememeber.

No, I emailed them a technical question.

emailed who ?

The people they offer for 'Technical questions'?

that's sales then.


Them was a about ants, pretyy good IIRC well at the time.

Eh?

https://en.wikipedia.org/wiki/Them!

One of my favourtie films when I was a kid when it came on TV , I did hide behind the chair, was about the same time doctor who had those leatherback beetles filmed with a macro camera lens to make them look really big, but I didn't understand such things at the time.

On Thu, 23 Nov 2017 07:51:17 -0800 (PST), whisky-dave
wrote:

snip

if I believe something is dangerous I need to take it out of action so thinking is important.

Yes, you do ... and it's not the taking it out of action that should
be the big decision but any delays in *not* taking it out of action.

snip

I didn't see any delays in NOT taking it out of action only delays in taking it out of action.

Quite.

and then we'd have to close the lab resulting in delayed corses and a back log.

Irrelevant. That's possibly like leaving the same insulation tiles on
other buildings like Grenfell because it will make them colder.

Nothing like that at all.

Everything like that mate. *If* something went wrong and you knew
about a potential issue but failed to do anything about it ...

But there was NO issue, an imaginged issue perhaps.

That's why I said 'potential' there. Only *today* have you found out
that there is no issue afa the supplier is concerned.



shrug See how much help they 'don't give' if you suggest there could
be a safety issue and therefore a potential threat to life.

which I can only do after I have checked them all.

Even one faulty one could be an issue ...

If it were faulty it might be, depending on the fault.

Quite.


but 'of course' you could
also rest more and I thought you said you already had (because you
kept denying it was likely to be a batch fault as they all acted the
same)?

I did a quick check on 3 of them when I found ONE to be giving 700W when I thought it should be around 1.7KW consumption.

No, you repeatedly asked why it wasn't actually 2000W. Then you added
that it dropped down to 700W and not zero.

That's why I asked
"So how much power does an oil filled radiator actually use"

What, you previously said they were all acting identically?

snip

It's not denial

Of course it is as you would have done something sooner rather than
arguing with me why there was no need and why you shouldn't?

I did the right thing it seems.

Really? How did you come to that conclusion (other than with
hindsight)?


I'm the one testing these things out, who else has done this.

You said you had a testing guy come in and do it any you were happy he
found them safe?

I was happy with the PAT tester who tests the equipment for electric safety.

And I never had any thoughts regarding their electrical safety.

Unless equipment has been checked I'm not allowed to use it unless it's new of course.

And you told us these were new and had just had 5 delivered. Then it
turns out the one you tested was a 2016 model?

snip

atually I first heard this from Data on star trek on the holodeck when he was playing sherlock.

I remember the episode.


But I hadn't eliminated the impossible.

So, what do you know today that you didn't know last week?

That's there's nothing wrong with the heaters

Supposedly, other than they aren't actually 2kW heaters etc.

and that if the 2KW was used as an indication of teh amount of heat they give off anyone using that in a calculation would get the wrong result if they were trying to calculate how many of these heaters would be required to perform the task of heating.

Quite.

Ere, a test I suggested and I don't think you have conducted yet is to
see how it performs (or works at all) just the high power element (No2
/ II) enabled? My thinking is that it might not overtemp cycle (or do
so as quickly) and so you would get more heat for a longer period,
maybe even continuously until the main thermostat cuts it out.



snip


for some strange reason yuo say yuo used the email address for sales where as I clicked on the link Log a Technical Query, which is what I have.

You accused me of contacting sales rather than TS. I contacted TS via
the email they offer for TS shrug.

yuo must have as you will NOT get technical support unless you enter your account code it's one of the red stared boxes that is compulsury,
* Required, account number and phone number.

*Unless* you email the address given it seems ...

I also DID NOT have a working phone both the office phone wa sout of action and so was teh so called emrgency phone.

So? I emailed Tech Support without requiring any account information
and without needing to use a phone.

Hey, some info for you .... if you phone many companies with the
intention of talking to TS, guess what, you often have to speak to
admin first. Then they put you though to TS.


Unless all those boxes are filled they won't or can't support you.

Quite (mug).

That is why I couldn't use tech support because I don't have the account code.

And that's why I could access TS because I used a method that didn't
require steps I couldn't answer. Simples Eh (even for you hopefully).

http://cpc.farnell.com/technical-support

I had to scroll down and use the Email technical support:

which is the product info email.

And I used the email given in the Technical Support field, so what?




Online Query Form: Log a Technical Query
Email:

two seperate email adresses and you told me sales had contected you .

No, I contacted sales, they spoke to TS and sales replied to me,
quoting the TS team.

snip

They seem to be safe to use in the teaching lab as they are, so I'm not worried from a H&S POV.

But maybe you should be, until they give you a formal 'all clear' in
any case?

which they have done proving I was right.

Do you also have issues dealing with timelines? At this point in the
conversation you hadn't said you had a reply.

snip

Quite possibly. How many people would plug one into a power meter?

same number of people that'd try to set fire to clading to see if it's safe as a building material I suspect.

You may well be right. ;-(

snip


Quite and it may have been and then a wiring error crept in ...

snip

If no one noticed then perhaps it's not an error at all, but a feature.

Why would it need such a feature if it worked as it should? You have
already stated the 'better quality' heater you have measured works
exactly as expected.

At best cycling the rad on an overtemp stat instead of the main stat
is a bodge.

snip

(Oh, what, with an 'overtemp stat', who would have thought! Lets hope
it still can't overheat when a student forgets they have left their
coat draped over it ...).

Well in that case I'd most likely notice

Let's hope then.

as I throw them at at 5pm, this is one reason we've always liked clearing the lab and before the £30k electrical upgrade at 4:45pm every 'night' I used to hit the main power emergency mushroom button switch ALL the electric OFF in the teaching labs in 251 & 253.

Ok.

Once the students knew there wasn't any power and couldn't find the trace on teh scope and the neons on the PSU had all gone out and when I started switching off the lights the studetns used to leave and there was NO power to the labs.

Ok.

snip


So for me this is now closed and I can re-install the heaters.

Even if that isn't actually the whole story at least you now have
something to cover your back etc.

That is my main aim yes, and teh reason I question managment when they told me to leave the heaters on over night when the datasheet/manual says do not leave them unattended.

Quite (however unrealistic for that sort of appliance).


Now you just need to get them to answer your first question re why
they aren't actually a 2kW heater. ;-)

I know why, 2KW is the maximum at 240V it indicates that on the label.

Good boy!

which is hy I expected less KW with the 23V max we get in the lab and why I wasn;lt too concerned in getting only 1.6KW at 202V

You only seemed 'less concerned when it was explained to you 20 times.

snip

As I suggested from the evidence of haing a heater that exibited this fault for 2 years so this 'fault'; had been in all these heaters sold over the last 2 years unlikely.

But not impossible (and this is new information to us remember).

Is anything impossible watson ;-)

Quite.

The information was new to me too I'd never run my office heater for long enough to question it's consumption or behavaour.

Ok.

It was only when I tried to work out why after about an hour why 5x2KW so about 40 amps didn't trip the 32 amp MCB (as I was told to leave them on over night, I wanted to see what would happen during the day)

Ok.

So I thought to myself maybe the voltage has dropped due to ohms law etc..
So I went to find our power meter which while it worked the batteries were flat, but the reading was 202V, I thought just maybe like some of our meters the battery being flat might have some effect on the reading.

Ok.

After putting the first heater on teh power meter I got a reading of about 1.6KW, after a few mins it went down to 680W.

Ok.

So like you I thought 'faulty heater',

No, I never actually considered them 'faulty' in a basic functionality
sense (as I explained why they were likely to be doing what you
observed), just that it was a questionable way to manage an overtemp
situation and therefore they *could* be faulty in how they had been
wired.

so I tried the next one and that was almost 700W and so was the 3rd.

Ok. So you tested 3 and now have tested 5 and only when you tested 5
did you not consider it a batch problem?

I don't think there is.

But we have already seen just how little you actually understand about
any of this by the amount of time people who do know have spent
correcting and re-explaining it all to you.

But they've all been wrong.

Oh really! I'm sure they will love to hear you think that.

The heaters are NOT faulty they are design to do that accring to those working for productinfo@CPC.

Yes, I know, but do they *actually* know that's how they were
originally designed to work or that's how they happen to work?


Which is why I tested them and from the results I got I concluded that rathter than there being a fault they were just cheap heaters, perhaps not up to the spec the datasheet might suggest.

So it seems.

But in doing said tests you revealed an anomaly that I don't believe
has yet been resolved.

For me it has.

I know ... especially as you didn't seem interested in even looking
into it in the fist place.

"the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat."

Yup, that's the overtemp stat I told you about at the beginning.

what's so hard to understand

To whom, you or me (given I was one of those explaining all of this to
you from the beginning)?

"an internal thermostat designed to lower the temperature",

Yup ... spot the clue there, *internal*. (No, I don't suppose you
would spot the clue or admit you are just digging more holes for
yourself).

no mention of any cut-out

Yup, but you missed it eh. ;-(

or thermal fuse

Nope, but I'll wager you £10 personally that there is one.

or circuit breaker

I never mentioned a circuit breaker.

the word trip only appears when talking about tipping the unit over.

So, you still don't understand how 'trip' can equal 'stat'? And your
'trip' there, I'd call a safety cutout.

Sounds like a stupid / trolling question then, especially if you
already knew all the answers?

I only klnew because I tested them whereas you just read the lable on the site.

Other than I have tested this exact same thing personally myself?

So what were your results ?

I've already explained it in detail.

Did you send yuor heater back ?

I didn't need to as I fully understood how they worked (in fact I
bought two more).


Did you log a technical query', you said sales contacted you.
rememeber.

No, I emailed them a technical question.

emailed who ?

The people they offer for 'Technical questions'?

that's sales then.

Nope, no more than you would often speak to reception before speaking
to anyone. I don't suppose you have ever heard of 'Technical Sales'
either have you?


Them was a about ants, pretyy good IIRC well at the time.

Eh?

https://en.wikipedia.org/wiki/Them!

Ah.

One of my favourtie films when I was a kid when it came on TV , I did hide behind the chair, was about the same time doctor who had those leatherback beetles filmed with a macro camera lens to make them look really big, but I didn't understand such things at the time.

And still don't seem to understand lots of things now eh. ;-)

Cheers, T i m

On 23/11/2017 13:31, whisky-dave wrote:
On Wednesday, 22 November 2017 20:02:36 UTC, John Rumm wrote:
On 22/11/2017 12:36, whisky-dave wrote:
On Tuesday, 21 November 2017 20:13:50 UTC, John Rumm wrote:
On 21/11/2017 11:29, whisky-dave wrote:
On Monday, 20 November 2017 19:03:54 UTC, John Rumm wrote:

Its much the same situation with a fuse. Both will permit
small overloads for a long duration. In some cases (much
depending on the installation method used for the cable)
even that may result in cable damage, or at the very least
premature ageing.

Yes I know, but what I don't know is whether a 32A MCB would
be used with cable that the MCB is not up to protecting.

For a general purpose ring circuit,


I'm not sure if that is the case, we are an electronics teaching
lab.

If it has a ring, and lots of sockets into which you can plug any
device you fancy, then its classed as a general purpose circuit.

fine.


(a non general purpose socket would be circuits for individual bits
of kit, like an immersion heater circuit or a fire alarm one -
i.e. situations where you know all about the specific
equipment/load at design time)

How about 'cleaners' sockets that don't go through the lab filter ?
or so we have been told which is called the dirty mains.

Still general purpose, since you don't know what will be powered from it
as such - i.e. its not dedicated to running a particular bit of equipment.

The only thing you might encounter different is in IT labs where
the large quantities of switched mode PSUs would often require that
high integrity earthing be used as well since there is often quite
high earth leakage when in normal operation as a result of all the
input filters / suppressors.

I'm not sure if 40 or so PCs and dozens of SMPS would count.

Probably would.

But all the lab sockets did have a filter on them.

Yup, nothing to do with high integrity earthing though.

(High integrity earthing just dictates that the earth be connected in a
ring (which on a ring circuit it naturally would be) and that separate
connections are used for each termination on the sockets - so sockets
with a pair of earth terminals are used).

Well here;s a link to our riser.
https://www.dropbox.com/s/u1rnoxretw..._0844.JPG?dl=0

the box opened is the one in the centre of the riser

https://www.dropbox.com/s/jr39axmtv0..._0845.JPG?dl=0

If that tells you anything.

Yup, normal memshield2 commercial style 3 phase CU. Which "room" is
yours?

251 PC lab, 252 Now the PCB room (this year), 253 the hardware lab
(my lab), 254 my office, 255 ex power lab with 3 phase installed.



However, some interesting things to note the

Many of those MCBs are not actually MCBs but RCBOs - i.e. they
include RCD and MCB functionality in one unit (this is good for a
situation like yours since any earth leakage faults will only take
out the affected circuit and not others). Although this does mean
that when seeing a trip, you need to decide if its an over-current
one or an earth leakage one.

Yes, but they have sfor the last 15 years+ just been refered to as
MCBs.

Perhaps, but that ain't what they are, and the difference is
significant. (you do have some normal MCBs in there, and also a three
phase switch (the one with the three dollies linked). All the RCBOs have
the test buttons.

Previuosly these were RCD and that;'s what they were called in the
days when it was my job to test them. Then that all changed with the
£30K upgrade to the labs electrics. I was then told NOT to test them
and that if they tripped we'd need to call the 'estates team' in to
come and sort any problem out. Which I must admit we tend to ignore,
unless of course something really serious happens.




(I don't know if the memshield2 RCBOs have a different "RCD
tripped" dolly position from the normal overcurrent tripped one -
Adam might know?).

me niether AFAIK I shouldn't even be opening the box.

The other interesting thing is that most of those socket circuits
are protected by C type devices. That means that the fault current
required to open one is double that which we have been discussing!
However the good news is that only applies to Live to Neutral
faults and not Live to Earth faults since the RCD part of the RCBO
will take care of those at =30mA.

Yes I thought it was something like that and this is also more likely
to happen when dealing with students. Than a short between live &
Neutral.

Its more likely in general. The design of most flat cables with the
earth in the middle makes it harder to create a LN short without also
creating a LE or NE one.

Yes I know I buy then, Quick blow, anti surge, time delay,
semi-delay, 'normal' I'm just glad I don't have to worry
about male and female and LGBTQ versions. Don't seem to nhave
those options with MCBs

You have a similar choice (at least for the larger loads):
Common nominal ratings of 3, 6, 10, 16, 20, 32, 40, 45, 50, 63
(and possibly others depending on range and brand)

Three different fault / inrush characteristics: Types B, C, &
D

And often a range of maximum breaking currents, typically 6kA,
and 10KA, but again there are others. (those plug in wylex
3036 rewireable replacements often only do 3kA)

The memshield2 breakers are often 10kA rated BTW - so higher
breaking capacity than most domestic stuff.

I wonder why, I'd have thought the cable would have vapourised long
before 10kA .

Nothing to do with the cable - more to do with the "stiffness" of the
supply. A big low impedance mains feed close to a substation can provide
very significant fault current[1]. This can pose a problem for the MCB
because there is an upper limit to the current flow it can successfully
interrupt. A typical domestic MCB will normally be rated for 6kA. So any
fault current less than that it should be able to open without
sustaining damage or welding its contacts together. More than that and
it may fail to disconnect or get destroyed while trying.

The memshield ones are aimed more at industrial use, and hence many can
cope with higher fault currents.

[1] Although your observations on voltage drop may suggest "big" and
"low impedance" are not words one would use for your supply!

I would assume that the installers that charged us £30k last
renovation had the sorted.

You know what they say about assumptions!

That they are like arse holes ?

No, that's opinions!

I've always thought that fault tripping was meant to go at 30ma
or less when there was an inbalance between of curretn detected
in the earth.

With a RCD or RCBO yes. Since you have RCBOs on the socket
circuits, then faults to earth will be cleared even if the circuits
don't meet the maximum allowed earth loop impedance.

That makes the whole situation less worrying, since the only fault
that won't be cleared is the less common L to N fault. (although
given the type C device there is probably no chance of clearing
such a fault on the instant part of the trip if you ever did get
one of those)


So it looks like what's been installed is what's needed in the lab
and up to standard so everythings OK.

With the exception of the loop impedance and voltage drop. The voltage
drop under load (combined with the voltage reduction device) means you
could damage equipment that is sensitive to undervolt. The loop
impedance (combined with the type C RCBOs) means its unlikely you would
clear a L to N fault without having to rely on the thermal trip
mechanism of the RCBO. So an increased fire risk.



Its the one in the table on the RHS of the graph:

http://wiki.diyfaq.org.uk/images/d/d...e-MCBTypeB.png

I wonder if 160A going through a student would cause any damage
or would it even be noticable, woul,d oit wake them up ?

To me it seems a bit late to trigger a fault if it takes 160A.

No, that's fine. You don't want it too low, or it would trip with
switch on surges. Remember the magnetic trip facility in the
MCB/RCBO is only there to deal with short circuit style situations,
and currents of hundreds of amps are normally commonplace in these
situations.

So as expected everything seems OK

Its less gloomy than it first appeared, but based on what currently
appears to be the situation, not all "ok".


Threre must be some reason why a B C or D would be installed.

Yup, B is general purpose and what you see in most domestic
installs (although I usually use type C on lighting circuits to
minimise nuisance trips on filament lamp failures).

That's interesting would the wiring in a typical lighting ring 320A
or how about 40A .

The nominal rating for a lighting MCB would be 6A. So the fault current
required to "instantly" trip a type B is 30A, or 60A for a type C

60A of fault current should be easy to realise on most lighting circuits
if the total circuit impedance is 3.8 ohms or less.

Type C is often used with high inrush loads (large transformers,
induction motors, large banks of strip lights etc).

I can imagine strip lights of the flourescant kind needing this, any
idea if its true of the recent LED tubes.

Generally less so... the strip lights (especially the older ones with
magnetic ballasts) can take quite a surge on startup and can present
quite and inductive load.

Type D is only usually used in industrial settings for things with
very high inrush.

Sounds sexy I wish we had kept some of the old power lab and HV
stuff. I remmeber being told how I'd have to phone up the royal
London hospital if we started up our HV lab as it cause interference
at the hospital and the generating board needed to be informed in
advance.


what happened to A ?

It was left out to avoid any confusion with the current rating of
the device, which would often be specified with "A".

I keep forgeting why in ohms law current is I if a student should
ask.

Comes from the French where the translation would be something like
"intensity of current"

(Ampere was of the French persuasion as well!)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Thursday, 23 November 2017 18:43:22 UTC, T i m wrote:
On Thu, 23 Nov 2017 07:51:17 -0800 (PST), whisky-dave
wrote:



Everything like that mate. *If* something went wrong and you knew
about a potential issue but failed to do anything about it ...

But there was NO issue, an imaginged issue perhaps.

That's why I said 'potential' there. Only *today* have you found out
that there is no issue afa the supplier is concerned.

So why has it now changed to a 'potential' issue ?
There will always be 'potential' issues about everything.
There's a potential' issue that a student might headbut the heater or fall over it.
There was a potential' issue where we''d have to close the lab for perhaps weeks putting all the courses back and the studetns complaining that they hadnt covered the work needed for the exams and tests.



shrug See how much help they 'don't give' if you suggest there could
be a safety issue and therefore a potential threat to life.

which I can only do after I have checked them all.

Even one faulty one could be an issue ...

If it were faulty it might be, depending on the fault.

Quite.

But as there wasn't a fault it's a bit like moving every single resident out of all tower blocks that have any form of cladding out of their homes, where would you put them all considering they haven't found homes for the majority of those still homeless from grenfell.
Sometimes you have to ignore the 'potential' issues and sort out the real issues.




I did a quick check on 3 of them when I found ONE to be giving 700W when I thought it should be around 1.7KW consumption.

No, you repeatedly asked why it wasn't actually 2000W. Then you added
that it dropped down to 700W and not zero.

No that isn't the case.


That's why I asked
"So how much power does an oil filled radiator actually use"

What, you previously said they were all acting identically?

Pretty much identically within my chosen parameters.



It's not denial

Of course it is as you would have done something sooner rather than
arguing with me why there was no need and why you shouldn't?

I did the right thing it seems.

Really? How did you come to that conclusion (other than with
hindsight)?

By thinking it through unlike you or the tech support that you contacted, maybe you should email the person you got tech support and tell them that they could have been resaponsable for the unnessary recall of 100s or 1000s of heaters.


I'm the one testing these things out, who else has done this.

You said you had a testing guy come in and do it any you were happy he
found them safe?

I was happy with the PAT tester who tests the equipment for electric safety.

And I never had any thoughts regarding their electrical safety.

So why contact tech support if there wasn't a problem ?

What happened to this 'potentail' issue you were refering to.




Unless equipment has been checked I'm not allowed to use it unless it's new of course.

And you told us these were new and had just had 5 delivered. Then it
turns out the one you tested was a 2016 model?

we have had issues heating this lab since the 1970s.
Over the years various ideas and solutions have been found and implemented.
Around 10 years ago the 1st was convection heaters were allowed in all offices but NOT in labs unless they were fixed to a wall.
Then all convection heaters had to be fixed to the wall, then H&S banned al convection heaters and they were replaced with oil filled radaitors at that time we didn't have any walls that we could mount radiators on. Then only offices were allowecd to have oil radiators and that is when I got mine in about ~2015.
It seemd to work OK,. The about a month ago after the building work disconnected all 'central' heating from the whole of the engineering building. When we asked what are they doing about the heating as it's 14C , they told us that they had ordered 20 x 2KW convenction heaters, it was then we informed them that they were banned by H&S years ago, so they cancellled that order and told us they ordered oil filled rads.
A few days later 5 of the 2KW heaters arrived YES 5 (the same as the ONE I've had in my office for 2 years) As I unpacked them I started to put them out switching each one on in turn. I placed them out across the whole of lab 253 on 2 seperate phases. My manager then said lets put them all on
one MCB to check to see what happens, lets see if the MCB is working and will cut out.



But I hadn't eliminated the impossible.

So, what do you know today that you didn't know last week?

That's there's nothing wrong with the heaters

Supposedly, other than they aren't actually 2kW heaters etc.

well that depends on what yuo want from a 2KW heater doesnt it.
It says on the label 2000W at 220V and 2000W at 240V, which to me seemed unlikey. So I would have suspected that the 2KW was for 240V and that it;s be abaout 1.8KW at 220V.
Would you have expected they would be 2KW at 200V how about 110V unlikkey you I didn't expected them to be 2KW whatever the voltage applied.
ONly yuo and a few of our worse students would expect 2KW if you connect a 9V battery between L-N because ity says it;s a 2KW heater.


and that if the 2KW was used as an indication of teh amount of heat they give off anyone using that in a calculation would get the wrong result if they were trying to calculate how many of these heaters would be required to perform the task of heating.

Quite.

and this is why I was asking the original Q .



Ere, a test I suggested and I don't think you have conducted yet is to
see how it performs (or works at all) just the high power element (No2
/ II) enabled?

Why that's doewsnt; give 2KW.
If you want 2KW both II and I need to be on.

My thinking is that it might not overtemp cycle (or do
so as quickly) and so you would get more heat for a longer period,
maybe even continuously until the main thermostat cuts it out.

the main thermostat shouldn't cut out until the room temerature is what yuo want it to be that's how the manual tells you to set up the heater, did you NOT read the instruction manual.



for some strange reason yuo say yuo used the email address for sales where as I clicked on the link Log a Technical Query, which is what I have..

You accused me of contacting sales rather than TS. I contacted TS via
the email they offer for TS shrug.

yuo must have as you will NOT get technical support unless you enter your account code it's one of the red stared boxes that is compulsury,
* Required, account number and phone number.

*Unless* you email the address given it seems ...

I also DID NOT have a working phone both the office phone wa sout of action and so was teh so called emrgency phone.

So? I emailed Tech Support without requiring any account information
and without needing to use a phone.

and the person you contacted said said them back .....


Hey, some info for you .... if you phone many companies with the
intention of talking to TS, guess what, you often have to speak to
admin first. Then they put you though to TS.

I had NO intention of phoning them.
1/ I didn't have a working phone
2/ I wanted it in writing so I could forward that on to whoever would need to send the heaters back and give the account details for remburment or a credit note or whatever.


Unless all those boxes are filled they won't or can't support you.

Quite (mug).

That is why I couldn't use tech support because I don't have the account code.

And that's why I could access TS because I used a method that didn't
require steps I couldn't answer. Simples Eh (even for you hopefully).

http://cpc.farnell.com/technical-support

I had to scroll down and use the Email technical support:

which is the product info email.

And I used the email given in the Technical Support field, so what?

that IS NOT tech support that is product info.

What email adress did you use to contact tech support. ?
Can you answer that ?


Online Query Form: Log a Technical Query
Email:

two seperate email adresses and you told me sales had contected you .

No, I contacted sales,

Just now yuo said yuo contacted tech supoport so which is it this time ?

they spoke to TS and sales replied to me,
quoting the TS team.

And what did TS allegedly say ?

They seem to be safe to use in the teaching lab as they are, so I'm not worried from a H&S POV.

But maybe you should be, until they give you a formal 'all clear' in
any case?

which they have done proving I was right.

Do you also have issues dealing with timelines? At this point in the
conversation you hadn't said you had a reply.

Because I hadn't.
I gave the times that I got a reply.


Quite possibly. How many people would plug one into a power meter?

same number of people that'd try to set fire to clading to see if it's safe as a building material I suspect.

You may well be right. ;-(

I always am ;-)


Quite and it may have been and then a wiring error crept in ...

snip

If no one noticed then perhaps it's not an error at all, but a feature.

Why would it need such a feature if it worked as it should?

what do you mean worked as it should ?
How would yuo expect a heater like this to work. ?
Don't forget the subject title of this post, like you have been.




You have
already stated the 'better quality' heater you have measured works
exactly as expected.

I sad my one at home works as I expect it to, didn't test it thoughly as I hadn't; found anything that I consider a bit weird/unusual or that I don't understand unlike those here.
Remember mine currently costs about £160 these here are about 1/4 the cost.


At best cycling the rad on an overtemp stat instead of the main stat
is a bodge.

Yes I thought that too a bodge from a cheap heater who'd have thought it ?
Not you for sure it seems.
It was my first thought.
But you still haven't explained what you mean by cycling and what do you expect ?



(Oh, what, with an 'overtemp stat', who would have thought! Lets hope
it still can't overheat when a student forgets they have left their
coat draped over it ...).

Well in that case I'd most likely notice

Let's hope then.

and even if I don't it's NOT a reason to return the heaters is it. ?



as I throw them at at 5pm, this is one reason we've always liked clearing the lab and before the £30k electrical upgrade at 4:45pm every 'night' I used to hit the main power emergency mushroom button switch ALL the electric OFF in the teaching labs in 251 & 253.

Ok.



Once the students knew there wasn't any power and couldn't find the trace on teh scope and the neons on the PSU had all gone out and when I started switching off the lights the studetns used to leave and there was NO power to the labs.

Ok.

So no problem existed in the past.



So for me this is now closed and I can re-install the heaters.

Even if that isn't actually the whole story at least you now have
something to cover your back etc.

That is my main aim yes, and teh reason I question managment when they told me to leave the heaters on over night when the datasheet/manual says do not leave them unattended.

Quite (however unrealistic for that sort of appliance).

I'm not sure why it is unrealistic.
I had a 500W version at home and I managed to only have that on when I was present or at home.


Now you just need to get them to answer your first question re why
they aren't actually a 2kW heater. ;-)

I know why, 2KW is the maximum at 240V it indicates that on the label.

Good boy!

Something you missed it seems.


which is hy I expected less KW with the 23V max we get in the lab and why I wasn;lt too concerned in getting only 1.6KW at 202V

You only seemed 'less concerned when it was explained to you 20 times.

NOT true.





Ok.

So like you I thought 'faulty heater',

No, I never actually considered them 'faulty'

So why suggest I contact tech support to send them back.

in a basic functionality
sense (as I explained why they were likely to be doing what you
observed), just that it was a questionable way to manage an overtemp
situation and therefore they *could* be faulty in how they had been
wired.

It could be, but after testing the 5 I considered such a thing unlikely it was far more likely that they did this down to cost.


so I tried the next one and that was almost 700W and so was the 3rd.

Ok. So you tested 3 and now have tested 5 and only when you tested 5
did you not consider it a batch problem?

I NEVER considered it a batch probem, I considered it a cheapness problem.
Or perhaps I expected to much from a 2KW heater that it should deliever 2KW of heat, again due to cheapness.


The heaters are NOT faulty they are design to do that accring to those working for productinfo@CPC.

Yes, I know,

So why do yuo suggest they are faulty ?
Why did you contact tech support ?



Which is why I tested them and from the results I got I concluded that rathter than there being a fault they were just cheap heaters, perhaps not up to the spec the datasheet might suggest.

So it seems.

So my intail interpretation I got from my tests was correct.


But in doing said tests you revealed an anomaly that I don't believe
has yet been resolved.

For me it has.

I know ... especially as you didn't seem interested in even looking
into it in the fist place.

I do you don't it's quite simple to see that.




"an internal thermostat designed to lower the temperature",

Yup ... spot the clue there, *internal*. (No, I don't suppose you
would spot the clue or admit you are just digging more holes for
yourself).

no mention of any cut-out

Yup, but you missed it eh. ;-(

No they are workign as designe dsomething you';ve missed completely.

On Thursday, 23 November 2017 21:19:50 UTC, John Rumm wrote:
On 23/11/2017 13:31, whisky-dave wrote:
On Wednesday, 22 November 2017 20:02:36 UTC, John Rumm wrote:
On 22/11/2017 12:36, whisky-dave wrote:
On Tuesday, 21 November 2017 20:13:50 UTC, John Rumm wrote:
On 21/11/2017 11:29, whisky-dave wrote:
On Monday, 20 November 2017 19:03:54 UTC, John Rumm wrote:

Its much the same situation with a fuse. Both will permit
small overloads for a long duration. In some cases (much
depending on the installation method used for the cable)
even that may result in cable damage, or at the very least
premature ageing.

Yes I know, but what I don't know is whether a 32A MCB would
be used with cable that the MCB is not up to protecting.

For a general purpose ring circuit,


I'm not sure if that is the case, we are an electronics teaching
lab.

If it has a ring, and lots of sockets into which you can plug any
device you fancy, then its classed as a general purpose circuit.

fine.


(a non general purpose socket would be circuits for individual bits
of kit, like an immersion heater circuit or a fire alarm one -
i.e. situations where you know all about the specific
equipment/load at design time)

How about 'cleaners' sockets that don't go through the lab filter ?
or so we have been told which is called the dirty mains.

Still general purpose, since you don't know what will be powered from it
as such - i.e. its not dedicated to running a particular bit of equipment..

General purpose for a lab I'd guess, other wise we wouldnlt have had ro specify we wanted an extra 4 to 8 sockets extra installed on each of the benches.


The only thing you might encounter different is in IT labs where
the large quantities of switched mode PSUs would often require that
high integrity earthing be used as well since there is often quite
high earth leakage when in normal operation as a result of all the
input filters / suppressors.

I'm not sure if 40 or so PCs and dozens of SMPS would count.

Probably would.

So I wouldn't consider it general purpose as in home general purpose.


But all the lab sockets did have a filter on them.

Yup, nothing to do with high integrity earthing though.

I wasn't aware they was a connection, and I don't think many homes have such a filter anmd consoder it general purpose.




Well here;s a link to our riser.
https://www.dropbox.com/s/u1rnoxretw..._0844.JPG?dl=0

the box opened is the one in the centre of the riser

https://www.dropbox.com/s/jr39axmtv0..._0845.JPG?dl=0

If that tells you anything.

Yup, normal memshield2 commercial style 3 phase CU. Which "room" is
yours?

251 PC lab, 252 Now the PCB room (this year), 253 the hardware lab
(my lab), 254 my office, 255 ex power lab with 3 phase installed.



However, some interesting things to note the

Many of those MCBs are not actually MCBs but RCBOs - i.e. they
include RCD and MCB functionality in one unit (this is good for a
situation like yours since any earth leakage faults will only take
out the affected circuit and not others). Although this does mean
that when seeing a trip, you need to decide if its an over-current
one or an earth leakage one.

Yes, but they have sfor the last 15 years+ just been refered to as
MCBs.

Perhaps, but that ain't what they are, and the difference is
significant.

Not to me since we've told this riser has nothing to do with us and if there is a problem we have to get someone in to sort it.



(you do have some normal MCBs in there, and also a three
phase switch (the one with the three dollies linked). All the RCBOs have
the test buttons.

Previuosly these were RCD and that;'s what they were called in the
days when it was my job to test them. Then that all changed with the
£30K upgrade to the labs electrics. I was then told NOT to test them
and that if they tripped we'd need to call the 'estates team' in to
come and sort any problem out. Which I must admit we tend to ignore,
unless of course something really serious happens.




(I don't know if the memshield2 RCBOs have a different "RCD
tripped" dolly position from the normal overcurrent tripped one -
Adam might know?).

me niether AFAIK I shouldn't even be opening the box.

The other interesting thing is that most of those socket circuits
are protected by C type devices. That means that the fault current
required to open one is double that which we have been discussing!
However the good news is that only applies to Live to Neutral
faults and not Live to Earth faults since the RCD part of the RCBO
will take care of those at =30mA.

Yes I thought it was something like that and this is also more likely
to happen when dealing with students. Than a short between live &
Neutral.

Its more likely in general. The design of most flat cables with the
earth in the middle makes it harder to create a LN short without also
creating a LE or NE one.

But every single one of our cables is round, never seen a flat one used in the lab adn we have 100s of them, I have 50+ unused still with the twist wore around them, 3 pin plug to IEC (mistakenly called a kettle lead) and they are all round cables.



Yes I know I buy then, Quick blow, anti surge, time delay,
semi-delay, 'normal' I'm just glad I don't have to worry
about male and female and LGBTQ versions. Don't seem to nhave
those options with MCBs

You have a similar choice (at least for the larger loads):
Common nominal ratings of 3, 6, 10, 16, 20, 32, 40, 45, 50, 63
(and possibly others depending on range and brand)

Three different fault / inrush characteristics: Types B, C, &
D

And often a range of maximum breaking currents, typically 6kA,
and 10KA, but again there are others. (those plug in wylex
3036 rewireable replacements often only do 3kA)

The memshield2 breakers are often 10kA rated BTW - so higher
breaking capacity than most domestic stuff.

I wonder why, I'd have thought the cable would have vapourised long
before 10kA .

Nothing to do with the cable - more to do with the "stiffness" of the
supply. A big low impedance mains feed close to a substation can provide
very significant fault current[1]. This can pose a problem for the MCB
because there is an upper limit to the current flow it can successfully
interrupt. A typical domestic MCB will normally be rated for 6kA. So any
fault current less than that it should be able to open without
sustaining damage or welding its contacts together. More than that and
it may fail to disconnect or get destroyed while trying.

The memshield ones are aimed more at industrial use, and hence many can
cope with higher fault currents.

So this doesn't sound much lioke a genral purpose setup to me.


[1] Although your observations on voltage drop may suggest "big" and
"low impedance" are not words one would use for your supply!

well that I don't know btu I expected a voltage drop as we exceeded the 32A..
I wasn't suprised that my 2KW heater only measured 1.6KW at 202V.



I would assume that the installers that charged us £30k last
renovation had the sorted.

You know what they say about assumptions!

That they are like arse holes ?

No, that's opinions!

why aren't assumptions the same, are yuo saying not everyone can have assumptions ?



So it looks like what's been installed is what's needed in the lab
and up to standard so everythings OK.

With the exception of the loop impedance and voltage drop. The voltage
drop under load (combined with the voltage reduction device) means you
could damage equipment that is sensitive to undervolt.

I don't believe we have such equipment, so I'm not particually worried.
But we have had problems in the PCB room but as yet it;s rare and hasn't been looked at closely.



So as expected everything seems OK

Its less gloomy than it first appeared, but based on what currently
appears to be the situation, not all "ok".

For me it is.


Threre must be some reason why a B C or D would be installed.

Yup, B is general purpose and what you see in most domestic
installs (although I usually use type C on lighting circuits to
minimise nuisance trips on filament lamp failures).

That's interesting would the wiring in a typical lighting ring 320A
or how about 40A .

The nominal rating for a lighting MCB would be 6A. So the fault current
required to "instantly" trip a type B is 30A, or 60A for a type C

So would the lighting cable be OK at these currents ?

60A of fault current should be easy to realise on most lighting circuits
if the total circuit impedance is 3.8 ohms or less.



Type C is often used with high inrush loads (large transformers,
induction motors, large banks of strip lights etc).

I can imagine strip lights of the flourescant kind needing this, any
idea if its true of the recent LED tubes.

Generally less so... the strip lights (especially the older ones with
magnetic ballasts) can take quite a surge on startup and can present
quite and inductive load.

So I would assume if e replaced our 70 odd floursenant tubes with LED version we wouldn't need to change the woring in the lihting circuit of teh lab.




Comes from the French where the translation would be something like
"intensity of current"

(Ampere was of the French persuasion as well!)

Bloody french, after 2 french GFs and a french flatmat think I've heard enough of the french ;-)

On 24/11/2017 12:39, whisky-dave wrote:
On Thursday, 23 November 2017 21:19:50 UTC, John Rumm wrote:
On 23/11/2017 13:31, whisky-dave wrote:

The only thing you might encounter different is in IT labs
where the large quantities of switched mode PSUs would often
require that high integrity earthing be used as well since
there is often quite high earth leakage when in normal
operation as a result of all the input filters / suppressors.

I'm not sure if 40 or so PCs and dozens of SMPS would count.

Probably would.

So I wouldn't consider it general purpose as in home general
purpose.

its can be general purpose and have high integrity earthing - the two
are not exclusive.

But all the lab sockets did have a filter on them.

Yup, nothing to do with high integrity earthing though.

I wasn't aware they was a connection, and I don't think many homes
have such a filter anmd consoder it general purpose.

Lots of places use mains filters of various types for IT kit. They are
(mostly) useless to be fair.

If you want proper protection for IT stuff, then either a line
interactive or online UPS is the way to go.

Perhaps, but that ain't what they are, and the difference is
significant.

Not to me since we've told this riser has nothing to do with us and
if there is a problem we have to get someone in to sort it.

Well its very relevant to the conversation we have been having and to
some of the questions you asked. It may not be your responsibility to
know about these things as a part of the job, but that does not mean you
have to pretend to be ignorant of the actual details.


Its more likely in general. The design of most flat cables with
the earth in the middle makes it harder to create a LN short
without also creating a LE or NE one.

But every single one of our cables is round, never seen a flat one
used in the lab adn we have 100s of them, I have 50+ unused still
with the twist wore around them, 3 pin plug to IEC (mistakenly called
a kettle lead) and they are all round cables.

Those are flexes not cables. The cables form part of the fixed wiring
between the CU and sockets etc.

Flexes are far more vulnerable to L to N faults than cables, but do have
the advantage of dedicated fault protection from the plug fuse.


The memshield2 breakers are often 10kA rated BTW - so higher
breaking capacity than most domestic stuff.

I wonder why, I'd have thought the cable would have vapourised
long before 10kA .

Nothing to do with the cable - more to do with the "stiffness" of
the supply. A big low impedance mains feed close to a substation
can provide very significant fault current[1]. This can pose a
problem for the MCB because there is an upper limit to the current
flow it can successfully interrupt. A typical domestic MCB will
normally be rated for 6kA. So any fault current less than that it
should be able to open without sustaining damage or welding its
contacts together. More than that and it may fail to disconnect or
get destroyed while trying.

The memshield ones are aimed more at industrial use, and hence many
can cope with higher fault currents.

So this doesn't sound much lioke a genral purpose setup to me.

If you look at that photo of your CU, all the "Ring room nnn" circuits
are general purpose circuits. The ones labelled things like "Door spur",
"door bell", "security panel" etc are not general purpose circuits.

(Note that general purpose has specific meaning in this context)

[1] Although your observations on voltage drop may suggest "big"
and "low impedance" are not words one would use for your supply!

well that I don't know btu I expected a voltage drop as we exceeded
the 32A. I wasn't suprised that my 2KW heater only measured 1.6KW at
202V.

Indeed you would expect a drop, but the amount you got was rather large.

So it looks like what's been installed is what's needed in the
lab and up to standard so everythings OK.

With the exception of the loop impedance and voltage drop. The
voltage drop under load (combined with the voltage reduction
device) means you could damage equipment that is sensitive to
undervolt.

I don't believe we have such equipment, so I'm not particually
worried.

A typical bit of kit to suffer would be something with a compressor
driven by an induction motor. Some fridges / freezers can be quite
sensitive, either having insufficient torque to start and stalling, or
drawing too much current and overheating.

But we have had problems in the PCB room but as yet it;s
rare and hasn't been looked at closely.

So as expected everything seems OK

Its less gloomy than it first appeared, but based on what
currently appears to be the situation, not all "ok".

For me it is.

Well that's ok then... for you.

Threre must be some reason why a B C or D would be
installed.

Yup, B is general purpose and what you see in most domestic
installs (although I usually use type C on lighting circuits
to minimise nuisance trips on filament lamp failures).

That's interesting would the wiring in a typical lighting ring
320A or how about 40A .

The nominal rating for a lighting MCB would be 6A. So the fault
current required to "instantly" trip a type B is 30A, or 60A for a
type C

So would the lighting cable be OK at these currents ?

Yup.

We can do an adiabatic check to be su

S = sqrt( 60^2 x 0.1 ) / 115 = 0.16 mm^2

Since the smallest lighting cable used is 1mm^2 (and 1.5mm^2 being
common in larger installations), you would have loads of headroom.

60A of fault current should be easy to realise on most lighting
circuits if the total circuit impedance is 3.8 ohms or less.



Type C is often used with high inrush loads (large
transformers, induction motors, large banks of strip lights
etc).

I can imagine strip lights of the flourescant kind needing this,
any idea if its true of the recent LED tubes.

Generally less so... the strip lights (especially the older ones
with magnetic ballasts) can take quite a surge on startup and can
present quite and inductive load.

So I would assume if e replaced our 70 odd floursenant tubes with LED
version we wouldn't need to change the woring in the lihting circuit
of teh lab.

The existing wiring as far as the fittings would be fine. With some
replacement tubes you would need to alter the wiring in the lamp fitting
to wire the ballast out of circuit.

(Although you can get some "straight replacement" LED retrofit tubes
that will work with the ballast)



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Fri, 24 Nov 2017 04:05:22 -0800 (PST), whisky-dave
wrote:

On Thursday, 23 November 2017 18:43:22 UTC, T i m wrote:
On Thu, 23 Nov 2017 07:51:17 -0800 (PST), whisky-dave
wrote:



Everything like that mate. *If* something went wrong and you knew
about a potential issue but failed to do anything about it ...

But there was NO issue, an imaginged issue perhaps.

That's why I said 'potential' there. Only *today* have you found out
that there is no issue afa the supplier is concerned.

So why has it now changed to a 'potential' issue ?

It was always a potential issue ...

There will always be 'potential' issues about everything.

No there won't.

There's a potential' issue that a student might headbut the heater or fall over it.

Grow up.

There was a potential' issue where we''d have to close the lab for perhaps weeks putting all the courses back and the studetns complaining that they hadnt covered the work needed for the exams and tests.

Or putting it all back longer if the lab caught fire.

snip

But as there wasn't a fault

How do you know?

it's a bit like moving every single resident out of all tower blocks that have any form of cladding out of their homes, where would you put them all considering they haven't found homes for the majority of those still homeless from grenfell.

No, so they take the cladding off the buildings eh.

Sometimes you have to ignore the 'potential' issues and sort out the real issues.

Quite.




I did a quick check on 3 of them when I found ONE to be giving 700W when I thought it should be around 1.7KW consumption.

No, you repeatedly asked why it wasn't actually 2000W. Then you added
that it dropped down to 700W and not zero.

No that isn't the case.

All there in black and white mate.


That's why I asked
"So how much power does an oil filled radiator actually use"

What, you previously said they were all acting identically?

Pretty much identically within my chosen parameters.

Whoosh.



It's not denial

Of course it is as you would have done something sooner rather than
arguing with me why there was no need and why you shouldn't?

I did the right thing it seems.

Really? How did you come to that conclusion (other than with
hindsight)?

By thinking it through unlike you

Bwhahaha ...

or the tech support that you contacted, maybe you should email the person you got tech support and tell them that they could have been resaponsable for the unnessary recall of 100s or 1000s of heaters.

Or saving a few lives ... only time will tell now eh.

snip

I was happy with the PAT tester who tests the equipment for electric safety.

And I never had any thoughts regarding their electrical safety.

So why contact tech support if there wasn't a problem ?

To make sure there wasn't.

What happened to this 'potentail' issue you were refering to.

It's still there mate.

snip

A few days later 5 of the 2KW heaters arrived YES 5 (the same as the ONE I've had in my office for 2 years)

Yes, I got that at the beginning.

snip

That's there's nothing wrong with the heaters

Supposedly, other than they aren't actually 2kW heaters etc.

well that depends on what yuo want from a 2KW heater doesnt it.

2k I would have though, assuming a 240V supply?

It says on the label 2000W at 220V and 2000W at 240V,

No it doesn't.

which to me seemed unlikey.

'Impossible' is the word you were looking for (for that sort of
device).

So I would have suspected that the 2KW was for 240V and that it;s be abaout 1.8KW at 220V.

Yup.

Would you have expected they would be 2KW at 200V how about 110V unlikkey you I didn't expected them to be 2KW whatever the voltage applied.

Would I? No, because I'm not stupid.

ONly yuo and a few of our worse students would expect 2KW if you connect a 9V battery between L-N because ity says it;s a 2KW heater.

Why would *I* expect that when I was the one (along with several
others) explaining it to you (over and over)?


and that if the 2KW was used as an indication of teh amount of heat they give off anyone using that in a calculation would get the wrong result if they were trying to calculate how many of these heaters would be required to perform the task of heating.

Quite.

and this is why I was asking the original Q .

No you weren't because if you were you would have had the thermal
calculations for the space.



Ere, a test I suggested and I don't think you have conducted yet is to
see how it performs (or works at all) just the high power element (No2
/ II) enabled?

Why that's doewsnt; give 2KW.

What?

If you want 2KW both II and I need to be on.

I know, I'm not you. Read it again.

My thinking is that it might not overtemp cycle (or do
so as quickly) and so you would get more heat for a longer period,
maybe even continuously until the main thermostat cuts it out.

the main thermostat shouldn't cut out until the room temerature is what yuo want it to be

I know, I'm not you.

the manual tells you to set up the heater, did you NOT read the instruction manual.

I didn't need to mate, I'm not you.

snip

So? I emailed Tech Support without requiring any account information
and without needing to use a phone.

and the person you contacted said said them back .....

No they didn't, stop making stuff up.

"Many thanks for your email and my apologies for this error.
Our technical team have advised that they believed this to be faulty.

If you can advise of the order details for this order this can be
logged for you."


Hey, some info for you .... if you phone many companies with the
intention of talking to TS, guess what, you often have to speak to
admin first. Then they put you though to TS.

I had NO intention of phoning them.

Whoosh.

1/ I didn't have a working phone

Whoosh.

2/ I wanted it in writing so I could forward that on to whoever would need to send the heaters back and give the account details for remburment or a credit note or whatever.

You didn't want it at all until I recommended you ask them.

snip

And I used the email given in the Technical Support field, so what?

that IS NOT tech support that is product info.

You are one *very* confused man.

What email adress did you use to contact tech support. ?

I've told you loads of times now and am not your wet nurse. Look it up
yourself.

Can you answer that ?

Yes (but see above).


Online Query Form: Log a Technical Query
Email:

two seperate email adresses and you told me sales had contected you .

No, I contacted sales,

Just now yuo said yuo contacted tech supoport so which is it this time ?

See above (and the previous explanations of how the world works).

they spoke to TS and sales replied to me,
quoting the TS team.

And what did TS allegedly say ?

I've told you loads of times now and am not your wet nurse. Look it up
yourself (and there is no allegedly about it, it's in black and
white).

They seem to be safe to use in the teaching lab as they are, so I'm not worried from a H&S POV.

But maybe you should be, until they give you a formal 'all clear' in
any case?

which they have done proving I was right.

Do you also have issues dealing with timelines? At this point in the
conversation you hadn't said you had a reply.

Because I hadn't.

So why did you type 'which they have done proving I was right' when
they hadn't at that point in our conversation.

I gave the times that I got a reply.

I know.


Quite possibly. How many people would plug one into a power meter?

same number of people that'd try to set fire to clading to see if it's safe as a building material I suspect.

You may well be right. ;-(

I always am ;-)

Yes, we know you think you are.

snip

Why would it need such a feature if it worked as it should?

what do you mean worked as it should ?

Like the other more expensive radiators do (as you told us yourself).
How difficult is all this for you?

How would yuo expect a heater like this to work. ?

I've told you loads of times now and am not your wet nurse. Look it up
yourself.

Don't forget the subject title of this post, like you have been.

Grow up.


You have
already stated the 'better quality' heater you have measured works
exactly as expected.

I sad my one at home works as I expect it to, didn't test it thoughly as I hadn't; found anything that I consider a bit weird/unusual or that I don't understand unlike those here.

Ok.

Remember mine currently costs about £160 these here are about 1/4 the cost.

So? Are you saying no cheaper product can work properly?


At best cycling the rad on an overtemp stat instead of the main stat
is a bodge.

Yes I thought that too a bodge from a cheap heater who'd have thought it ?

No you didn't and I don't think you do now. You don't even know what
an overtemp stat is!

Not you for sure it seems.

Grow up.

It was my first thought.

Liar.

But you still haven't explained what you mean by cycling and what do you expect ?

And I'm not going to again as I have done so many times already.


(Oh, what, with an 'overtemp stat', who would have thought! Lets hope
it still can't overheat when a student forgets they have left their
coat draped over it ...).

Well in that case I'd most likely notice

Let's hope then.

and even if I don't it's NOT a reason to return the heaters is it. ?

What, because the overtemp function isn't in circuit on the low power
setting? You work it out.

snip

That is my main aim yes, and teh reason I question managment when they told me to leave the heaters on over night when the datasheet/manual says do not leave them unattended.

Quite (however unrealistic for that sort of appliance).

I'm not sure why it is unrealistic.

Because a properly designed oil filled rad is very reliable and safe.

I had a 500W version at home and I managed to only have that on when I was present or at home.

Whoosh.


snip

which is hy I expected less KW with the 23V max we get in the lab and why I wasn;lt too concerned in getting only 1.6KW at 202V

You only seemed 'less concerned when it was explained to you 20 times.

NOT true.

Doesn't look like it from reading what you wrote ...


So like you I thought 'faulty heater',

No, I never actually considered them 'faulty'

So why suggest I contact tech support

To have their functionality confirmed / checked in principal.

to send them back.

Stop making stuff up.

in a basic functionality
sense (as I explained why they were likely to be doing what you
observed), just that it was a questionable way to manage an overtemp
situation and therefore they *could* be faulty in how they had been
wired.

It could be, but after testing the 5 I considered such a thing unlikely it was far more likely that they did this down to cost.

Or incorrect wiring. *You* explain how not also running the 700W
element through the upper limit stat is down to cost.


so I tried the next one and that was almost 700W and so was the 3rd.

Ok. So you tested 3 and now have tested 5 and only when you tested 5
did you not consider it a batch problem?

I NEVER considered it a batch probem, I considered it a cheapness problem.

But didn't know why.

Or perhaps I expected to much from a 2KW heater that it should deliever 2KW of heat, again due to cheapness.

But it does deliver 2kW of heat.


The heaters are NOT faulty they are design to do that accring to those working for productinfo@CPC.

Yes, I know,

So why do yuo suggest they are faulty ?

Because I believe they could be.

Why did you contact tech support ?

To see if they thought they were.



Which is why I tested them and from the results I got I concluded that rathter than there being a fault they were just cheap heaters, perhaps not up to the spec the datasheet might suggest.

So it seems.

So my intail interpretation I got from my tests was correct.

I wouldn't have said initial.


But in doing said tests you revealed an anomaly that I don't believe
has yet been resolved.

For me it has.

I know ... especially as you didn't seem interested in even looking
into it in the fist place.

I do you don't it's quite simple to see that.

How many times did I suggest you run it past their TS and have you
argue and question why you should.


"an internal thermostat designed to lower the temperature",

Yup ... spot the clue there, *internal*. (No, I don't suppose you
would spot the clue or admit you are just digging more holes for
yourself).

no mention of any cut-out

Yup, but you missed it eh. ;-(

No they are workign as designe dsomething you';ve missed completely.

As you have no way of proving that, once again you are like a sniper
using bollox for ammunition. ;-(

All you can say with any certainty is that they are working as they
are working. You have *no idea* if they are working as originally
designed.

Cheers, T i m

On Friday, 24 November 2017 18:30:24 UTC, John Rumm wrote:
On 24/11/2017 12:39, whisky-dave wrote:
On Thursday, 23 November 2017 21:19:50 UTC, John Rumm wrote:
On 23/11/2017 13:31, whisky-dave wrote:

The only thing you might encounter different is in IT labs
where the large quantities of switched mode PSUs would often
require that high integrity earthing be used as well since
there is often quite high earth leakage when in normal
operation as a result of all the input filters / suppressors.

I'm not sure if 40 or so PCs and dozens of SMPS would count.

Probably would.

So I wouldn't consider it general purpose as in home general
purpose.

its can be general purpose and have high integrity earthing - the two
are not exclusive.

Well as long as someone else knows when and when not to install high integrity earthing, I've no idea.


But all the lab sockets did have a filter on them.

Yup, nothing to do with high integrity earthing though.

I wasn't aware they was a connection, and I don't think many homes
have such a filter anmd consoder it general purpose.

Lots of places use mains filters of various types for IT kit. They are
(mostly) useless to be fair.

Are yuo sugegsting managment could be fooled by the company installing their prodicts ;-)


If you want proper protection for IT stuff, then either a line
interactive or online UPS is the way to go.

But what if you have a mix of uses in a lab.
This isn't an IT lab, we have aa whole 3 floor building for that.


Perhaps, but that ain't what they are, and the difference is
significant.

Not to me since we've told this riser has nothing to do with us and
if there is a problem we have to get someone in to sort it.

Well its very relevant to the conversation we have been having and to
some of the questions you asked. It may not be your responsibility to
know about these things as a part of the job, but that does not mean you
have to pretend to be ignorant of the actual details.

There are NO problems that I can see.
Whatever happened to trip the MCB, now if the MCB hadn't tripped would that have been a problem ?


Its more likely in general. The design of most flat cables with
the earth in the middle makes it harder to create a LN short
without also creating a LE or NE one.

But every single one of our cables is round, never seen a flat one
used in the lab adn we have 100s of them, I have 50+ unused still
with the twist wore around them, 3 pin plug to IEC (mistakenly called
a kettle lead) and they are all round cables.

Those are flexes not cables.

We call them cables not flexes.

https://www.rapidonline.com/unistran...-cable-01-0230

https://uk.rs-online.com/web/p/mains...cable/0491879/


The cables form part of the fixed wiring
between the CU and sockets etc.

Our students don't get access to them as they are in conduit.
Students don't get access to them.

So the only flat cables our students ever see are IDC ribbon cables, for them that is what a flat cable is.


Flexes are far more vulnerable to L to N faults than cables, but do have
the advantage of dedicated fault protection from the plug fuse.


The memshield2 breakers are often 10kA rated BTW - so higher
breaking capacity than most domestic stuff.

I wonder why, I'd have thought the cable would have vapourised
long before 10kA .

Nothing to do with the cable - more to do with the "stiffness" of
the supply. A big low impedance mains feed close to a substation
can provide very significant fault current[1]. This can pose a
problem for the MCB because there is an upper limit to the current
flow it can successfully interrupt. A typical domestic MCB will
normally be rated for 6kA. So any fault current less than that it
should be able to open without sustaining damage or welding its
contacts together. More than that and it may fail to disconnect or
get destroyed while trying.

The memshield ones are aimed more at industrial use, and hence many
can cope with higher fault currents.

So this doesn't sound much lioke a genral purpose setup to me.

If you look at that photo of your CU, all the "Ring room nnn" circuits
are general purpose circuits. The ones labelled things like "Door spur",
"door bell", "security panel" etc are not general purpose circuits.

Strangly enough none of those are in use, haven't been for years.


(Note that general purpose has specific meaning in this context)



[1] Although your observations on voltage drop may suggest "big"
and "low impedance" are not words one would use for your supply!

well that I don't know btu I expected a voltage drop as we exceeded
the 32A. I wasn't suprised that my 2KW heater only measured 1.6KW at
202V.

Indeed you would expect a drop, but the amount you got was rather large.

Well that woukd depend on the 'Zero' no load point wouldn't it I mean if the voltage off load starts at 223V rather than 240 or even 230......


So it looks like what's been installed is what's needed in the
lab and up to standard so everythings OK.

With the exception of the loop impedance and voltage drop. The
voltage drop under load (combined with the voltage reduction
device) means you could damage equipment that is sensitive to
undervolt.

I don't believe we have such equipment, so I'm not particually
worried.

A typical bit of kit to suffer would be something with a compressor
driven by an induction motor. Some fridges / freezers can be quite
sensitive, either having insufficient torque to start and stalling, or
drawing too much current and overheating.

Interesting you should ay that as on friday or CNC machine cut out, this has a densist grade compressor attacheted to it adn because the room was cold a heater too room 252. Today no ones in their it's cold nothing is on and the mains voltage measure 216V .


But we have had problems in the PCB room but as yet it;s
rare and hasn't been looked at closely.

So that could be whats been going wrong.



So as expected everything seems OK

Its less gloomy than it first appeared, but based on what
currently appears to be the situation, not all "ok".

For me it is.

Well that's ok then... for you.

Yep, as I've said and the previous managers have saiud the heating in the lab or department hasblt worked in 35+ years why don't you fix it.



Threre must be some reason why a B C or D would be
installed.

Yup, B is general purpose and what you see in most domestic
installs (although I usually use type C on lighting circuits
to minimise nuisance trips on filament lamp failures).

That's interesting would the wiring in a typical lighting ring
320A or how about 40A .

The nominal rating for a lighting MCB would be 6A. So the fault
current required to "instantly" trip a type B is 30A, or 60A for a
type C

So would the lighting cable be OK at these currents ?

Yup.

We can do an adiabatic check to be su

S = sqrt( 60^2 x 0.1 ) / 115 = 0.16 mm^2

Since the smallest lighting cable used is 1mm^2 (and 1.5mm^2 being
common in larger installations), you would have loads of headroom.

I wonder why they don't give similar headroom for general purpose mains.


60A of fault current should be easy to realise on most lighting
circuits if the total circuit impedance is 3.8 ohms or less.



Type C is often used with high inrush loads (large
transformers, induction motors, large banks of strip lights
etc).

I can imagine strip lights of the flourescant kind needing this,
any idea if its true of the recent LED tubes.

Generally less so... the strip lights (especially the older ones
with magnetic ballasts) can take quite a surge on startup and can
present quite and inductive load.

So I would assume if e replaced our 70 odd floursenant tubes with LED
version we wouldn't need to change the woring in the lihting circuit
of teh lab.

The existing wiring as far as the fittings would be fine. With some
replacement tubes you would need to alter the wiring in the lamp fitting
to wire the ballast out of circuit.

We replaced 4 tubes will LED versions without rewiring they seem to work fine.


(Although you can get some "straight replacement" LED retrofit tubes
that will work with the ballast)



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Friday, 24 November 2017 23:56:22 UTC, T i m wrote:
On Fri, 24 Nov 2017 04:05:22 -0800 (PST), whisky-dave
wrote:

On Thursday, 23 November 2017 18:43:22 UTC, T i m wrote:
On Thu, 23 Nov 2017 07:51:17 -0800 (PST), whisky-dave
wrote:



Everything like that mate. *If* something went wrong and you knew
about a potential issue but failed to do anything about it ...

But there was NO issue, an imaginged issue perhaps.

That's why I said 'potential' there. Only *today* have you found out
that there is no issue afa the supplier is concerned.

So why has it now changed to a 'potential' issue ?

It was always a potential issue ...

A meaningless statement then.


There will always be 'potential' issues about everything.

No there won't.

So why were these heaters always a potential issue ?


There's a potential' issue that a student might headbut the heater or fall over it.

Grow up.

Those are issues in a teaching lab I did have one student walk into one hitting his knee and nearly knocking it over.
Another student turned a heater down as it was too close to his head.



There was a potential' issue where we''d have to close the lab for perhaps weeks putting all the courses back and the studetns complaining that they hadnt covered the work needed for the exams and tests.

Or putting it all back longer if the lab caught fire.


Then at least they'd be forced to do something about it.


snip

But as there wasn't a fault

How do you know?

No one has found one.



it's a bit like moving every single resident out of all tower blocks that have any form of cladding out of their homes, where would you put them all considering they haven't found homes for the majority of those still homeless from grenfell.

No, so they take the cladding off the buildings eh.

Then why was the cladding put on ?


Sometimes you have to ignore the 'potential' issues and sort out the real issues.

Quite.



I did a quick check on 3 of them when I found ONE to be giving 700W when I thought it should be around 1.7KW consumption.

No, you repeatedly asked why it wasn't actually 2000W. Then you added
that it dropped down to 700W and not zero.

No that isn't the case.

All there in black and white mate.

then go find it.
I have NEVER asked why the heaters are at 1600, 1700, 1800 or 1900 instead of 2000W





Bwhahaha ...

General Melchett I presume.


or the tech support that you contacted, maybe you should email the person you got tech support and tell them that they could have been resaponsable for the unnessary recall of 100s or 1000s of heaters.

Or saving a few lives ... only time will tell now eh.

And if your version of tech support is anything to go by.


I was happy with the PAT tester who tests the equipment for electric safety.

And I never had any thoughts regarding their electrical safety.

So why contact tech support if there wasn't a problem ?

To make sure there wasn't.

and yuor tech suppoort said return then where as my productinfo said they are designe dto switch down to 700W. Pity tech support didn't know the product itself.



What happened to this 'potentail' issue you were refering to.

It's still there mate.

Still where ?

Those that make the product have said it was designed that way.
SO the potential issue is no longer a potential issue.



A few days later 5 of the 2KW heaters arrived YES 5 (the same as the ONE I've had in my office for 2 years)

Yes, I got that at the beginning.

you seemed to be confused over it.


That's there's nothing wrong with the heaters

Supposedly, other than they aren't actually 2kW heaters etc.

well that depends on what yuo want from a 2KW heater doesnt it.

2k I would have though, assuming a 240V supply?

Yes that's what I would have thought.
SO when I saw that only 1.6KW was being drawn at 202V unlike you I wasn't suprised, what did suprise me was that it went down to 700W.



It says on the label 2000W at 220V and 2000W at 240V,

No it doesn't.

yes it does.
220-240V- 50Hz 2000W

Unless of course you tell me what the label actualy means.


So I would have suspected that the 2KW was for 240V and that it;s be abaout 1.8KW at 220V.

Yup.

Would you have expected they would be 2KW at 200V how about 110V unlikkey you I didn't expected them to be 2KW whatever the voltage applied.

Would I? No, because I'm not stupid.


ONly yuo and a few of our worse students would expect 2KW if you connect a 9V battery between L-N because ity says it;s a 2KW heater.

Why would *I* expect that when I was the one (along with several
others) explaining it to you (over and over)?

You still got it wroing though didn't you.



and this is why I was asking the original Q .

No you weren't because if you were you would have had the thermal
calculations for the space.

Why would I have the thermal calculations for the space ?


2/ I wanted it in writing so I could forward that on to whoever would need to send the heaters back and give the account details for remburment or a credit note or whatever.

You didn't want it at all until I recommended you ask them.

I didn't think there was anything faulty with the 5 heaters.
and I have been proved right, by those that actually know the product.

I will take their (those that know the product) word for it over some idiot like you.

On Mon, 27 Nov 2017 04:07:19 -0800 (PST), whisky-dave
wrote:

snip

There will always be 'potential' issues about everything.

No there won't.

So why were these heaters always a potential issue ?

Because *you* noticed a functional anomaly from the get go.

snip

But as there wasn't a fault

How do you know?

No one has found one.

So that means one can't exist it your mind does it (to say 'there
wasn't a fault')?

snip

Or saving a few lives ... only time will tell now eh.

And if your version of tech support is anything to go by.

And if your (first) version of tech support is anything to go by?


I was happy with the PAT tester who tests the equipment for electric safety.

And I never had any thoughts regarding their electrical safety.

So why contact tech support if there wasn't a problem ?

To make sure there wasn't.

and yuor tech suppoort said return then

LIAR!

where as my productinfo said they are designe dto switch down to 700W.

Yes, so they say.

Pity tech support didn't know the product itself.

Quite.



What happened to this 'potentail' issue you were refering to.

It's still there mate.

Still where ?

Where it always was.

Those that make the product have said it was designed that way.

Oh, you have spoken to the manufacturers as well now have you?

SO the potential issue is no longer a potential issue.

Yup, still is, as even a technical numbskull like you should be able
to see. Put the radiator on 700W and the stat on full and chuck a big
coat over it and see what happens. If you are confident there are no
safety issues, leave it like that overnight.

snip

snip

It says on the label 2000W at 220V and 2000W at 240V,

No it doesn't.

yes it does.
220-240V- 50Hz 2000W

Exactly ... that NOT what you *lied* about above eh. You keep lying as
an attempt to move the goalpost.

Unless of course you tell me what the label actualy means.

'Unless?' You know what everything means apparently. That doesn't
explain why you had to ask about it all (inc about the MCB that was an
RCBO and how many heaters you would need to heat that space etc).

snip

Why would *I* expect that when I was the one (along with several
others) explaining it to you (over and over)?

You still got it wroing though didn't you.

Nope.



and this is why I was asking the original Q .

No you weren't because if you were you would have had the thermal
calculations for the space.

Why would I have the thermal calculations for the space ?

You wouldn't, but to answer the question you asked about it you would
have to attain them and you were given the means (that you still
didn't do nor understand).


2/ I wanted it in writing so I could forward that on to whoever would need to send the heaters back and give the account details for remburment or a credit note or whatever.

You didn't want it at all until I recommended you ask them.

I didn't think there was anything faulty with the 5 heaters.

I know, you keep saying for some reason.

and I have been proved right, by those that actually know the product.

Bwhahaha. Course you were and they do.

I will take their (those that know the product) word for it over some idiot like you.

Aww bless.

Like I said, if you are so confident the rad is 'safe' that way, do
the coat / blanket experiment (or see how long it runs before it shuts
off permanently for reasons you will never accept).

And I'm still waiting for the results of the 1300W element only test?
Oh yes, you asked what 'cycling' meant didn't you because that was
something else you didn't know ...

Cheers, T i m

On Monday, 27 November 2017 13:24:38 UTC, T i m wrote:
On Mon, 27 Nov 2017 04:07:19 -0800 (PST), whisky-dave
wrote:

snip

There will always be 'potential' issues about everything.

No there won't.

So why were these heaters always a potential issue ?

Because *you* noticed a functional anomaly from the get go.

And that functional anomaly has now be confurmed to be operating as it should according to the productinfo people whom I;d assume know more about their product specs than sales.


But as there wasn't a fault

How do you know?

No one has found one.

So that means one can't exist it your mind does it (to say 'there
wasn't a fault')?

There's a fault in your head too have you got proof there aren't any ?

I think the heaters are working exactly as they were designed to work no fault.
Would yuo really send them back and then send the replacements back and then sent the second set of replacements back, and teh 3rd and the 4th.
Because according to you they have a fault.

Threr;s only one fault and it's in your head.




Or saving a few lives ... only time will tell now eh.

And if your version of tech support is anything to go by.

And if your (first) version of tech support is anything to go by?

The first thing is to satiffy the customer and to make sure the person reading the email can;t be blammed for not saying send the faulkty product back.
Then they ask someone that knows what they are doing someone with an actual skill or someone that can read a manual or actually think, or they can contact those that make the product.



I was happy with the PAT tester who tests the equipment for electric safety.

And I never had any thoughts regarding their electrical safety.

So why contact tech support if there wasn't a problem ?

To make sure there wasn't.

and yuor tech suppoort said return then

LIAR!

Short mememory haven't you. whoever you said you contacted suggested they should be returned.





where as my productinfo said they are designe dto switch down to 700W.

Yes, so they say.

So for me there's no problem then, if they were designed to do that, some here suggested faulty wiring as tehy were meant to switch off.


Pity tech support didn't know the product itself.

Quite.



What happened to this 'potentail' issue you were refering to.

It's still there mate.

Still where ?

Where it always was.

and where it will stay (ifn there is one) without being a problem.

Unless you can tell me exaclt ywhat the 'potentail' issue is, but I'm betting yuo can't.





Those that make the product have said it was designed that way.

Oh, you have spoken to the manufacturers as well now have you?

I haven't spoken to anyone (and neither have you so what are these potentail issues you speak of) but those at product info said.
-----------------------------------
"Unfortunately there was confusion over our initial response, the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat.

We are sorry for any inconvenience caused."
---------------------------------------------

Can you understand those simple words are they too difficult for you.

Where it says.
"the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat"

NO WHERE does it say the heater switches OFF.
NO WHERE does it say the heater phones home or is a danger if it switches down to 700W

So where do you get the idea that the heaters are faulty, it;s yuor head that;s faulty nothing else.







SO the potential issue is no longer a potential issue.

Yup, still is,

No it isn't.

as even a technical numbskull like you should be able
to see. Put the radiator on 700W

yuo can;t pu it on 700W ****wit.

and the stat on full and chuck a big
coat over it and see what happens. If you are confident there are no
safety issues, leave it like that overnight.

Then stick your fingers in an electric light socket, then surely we should send all electric light sockets back shouldn't we.

What about the potential of peole runnjng oput in front of cars, are yuo saying send all the cars back for repair ?

On Mon, 27 Nov 2017 05:52:01 -0800 (PST), whisky-dave
wrote:

On Monday, 27 November 2017 13:24:38 UTC, T i m wrote:
On Mon, 27 Nov 2017 04:07:19 -0800 (PST), whisky-dave
wrote:

snip

There will always be 'potential' issues about everything.

No there won't.

So why were these heaters always a potential issue ?

Because *you* noticed a functional anomaly from the get go.

And that functional anomaly has now be confurmed to be operating as it should according to the productinfo people whom I;d assume know more about their product specs than sales.

Yup, and we are back to the assumptions ...

snip

I think the heaters are working exactly as they were designed to work no fault.

That's good then.

Would yuo really send them back and then send the replacements back and then sent the second set of replacements back, and teh 3rd and the 4th.

'Would I really?' No, I really wouldn't.

Because according to you they have a fault.

Where have I ever said that?

Threr;s only one fault and it's in your head.

Do the test coat test if you are so sure ...

Or saving a few lives ... only time will tell now eh.

And if your version of tech support is anything to go by.

And if your (first) version of tech support is anything to go by?

The first thing is to satiffy the customer and to make sure the person reading the email can;t be blammed for not saying send the faulkty product back.

Ok?

Then they ask someone that knows what they are doing


And who was that (assuming it wasn't your last and only valid option).

someone with an actual skill

So that would be an electric design / testing engineer then.

or someone that can read a manual

It's not covered in the manual.

or actually think,

So not you then, you have to ask here.

or they can contact those that make the product.

Ah. Glad you got there in the end. And you / they have done that have
they, I'd like to see their reply?



I was happy with the PAT tester who tests the equipment for electric safety.

And I never had any thoughts regarding their electrical safety.

So why contact tech support if there wasn't a problem ?

To make sure there wasn't.

and yuor tech suppoort said return then

LIAR!

Short mememory haven't you.

Nope.

"Hello,

Many thanks for your email and my apologies for this error.
Our technical team have advised that they believed this to be faulty.

If you can advise of the order details for this order this can be
logged for you.

Kind regards,

CPC Sales team"

whoever you said you contacted suggested they should be returned.

Nope:

"Hello,

Many thanks for your email and my apologies for this error.
Our technical team have advised that they believed this to be faulty.

If you can advise of the order details for this order this can be
logged for you.

Kind regards,

CPC Sales team"


where as my productinfo said they are designe dto switch down to 700W.

Yes, so they say.

So for me there's no problem then,

Good for you ... so you will be happy to do the overnight coat test
yes?

if they were designed to do that,

Ah, I think he's getting closer ... *IF*.

some here suggested faulty wiring as tehy were meant to switch off.

Yes, me, all part of the same potential issue.

snip

Unless you can tell me exaclt ywhat the 'potentail' issue is, but I'm betting yuo can't.

How much you willing to bet mate? £100?

snip

Oh, you have spoken to the manufacturers as well now have you?

I haven't spoken to anyone

You are a liar then (or so stupid you don't understand that an email
correspondence includes 'speaking to someone' in that context).

(and neither have you so what are these potential issues you speak of)

I have (see above).

but those at product info said.

-----------------------------------
"Unfortunately there was confusion over our initial response, the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat.

Yes, but a 'drop in power' isn't the same as 'turning all the elements
off in the light of an overheat condition' is it?

We are sorry for any inconvenience caused."
---------------------------------------------

Can you understand those simple words are they too difficult for you.

Whoosh.

So, when Vauxhall says 'There are no issues with your Zafira', you
will be happy to sit there when it is in flames around you'?

Where it says.
"the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat"

I know, I told you that is was there and exactly what it did ... and
you argued many times that it even existed.

NO WHERE does it say the heater switches OFF.

I never said it did, just that I feel it would be safer if it did.

NO WHERE does it say the heater phones home or is a danger if it switches down to 700W

Grow up.

So where do you get the idea that the heaters are faulty, it;s yuor head that;s faulty nothing else.

That's your call mate. Done the coat test yet?


SO the potential issue is no longer a potential issue.

Yup, still is,

No it isn't.

Yes it is. That fact that you don't understand what it is doesn't stop
it existing.

as even a technical numbskull like you should be able
to see. Put the radiator on 700W

yuo can;t pu it on 700W ****wit.

Of course you can, you just flick the first switch on (really, are you
*that* stupid)???!!!

and the stat on full and chuck a big
coat over it and see what happens. If you are confident there are no
safety issues, leave it like that overnight.

Then stick your fingers in an electric light socket, then surely we should send all electric light sockets back shouldn't we.

Grow up. Do the test if you are so sure of yourself.

What about the potential of peole runnjng oput in front of cars, are yuo saying send all the cars back for repair ?

Grow up. You are making yourself look more stupid than normal and just
digging yourself in deeper and deeper mate.

Switch it to 700W, turn the thermostat up to full, chuck a big coat
over it and go home for the evening.

Hopefully, you will just have a warm coat (or a dead rad) in the
morning, not being held back by the fire brigade.

Cheers, T i m

On Monday, 27 November 2017 16:12:24 UTC, T i m wrote:
On Mon, 27 Nov 2017 05:52:01 -0800 (PST), whisky-dave
wrote:

On Monday, 27 November 2017 13:24:38 UTC, T i m wrote:
On Mon, 27 Nov 2017 04:07:19 -0800 (PST), whisky-dave
wrote:

snip

There will always be 'potential' issues about everything.

No there won't.

So why were these heaters always a potential issue ?

Because *you* noticed a functional anomaly from the get go.

And that functional anomaly has now be confurmed to be operating as it should according to the productinfo people whom I;d assume know more about their product specs than sales.

Yup, and we are back to the assumptions ...

Like most things in the universe, well sorted.



I think the heaters are working exactly as they were designed to work no fault.

That's good then.

Yes it is.


Would yuo really send them back and then send the replacements back and then sent the second set of replacements back, and teh 3rd and the 4th.

'Would I really?' No, I really wouldn't.

Well that's good I don't planing on sending them back either, now I know they are working as designed.


Because according to you they have a fault.

Where have I ever said that?

Well if you can't even follow what you've said.



Threr;s only one fault and it's in your head.

Do the test coat test if you are so sure ...

I don't need to, the coat test wouldn't prove anything.

Anymore than you need to drive a car onto a bridge and kill people to prove that there is a potential issue with cars.
So why doesn't everyone send their cars back because they have potential issues ?




The first thing is to satiffy the customer and to make sure the person reading the email can;t be blammed for not saying send the faulkty product back.

Ok?

Yes in teh customer is always right first thinmg yuo do is agree with THEM.
When I kleft school I worked in a supermarket during teh summer and there I waas told the let the customer think they are right even if they aren't.


Then they ask someone that knows what they are doing


And who was that (assuming it wasn't your last and only valid option).

No idea and I don't care.

They aplogised for their error.

"Unfortunately there was confusion over our initial response,"

Is that so difficult for you to understand ?





someone with an actual skill

So that would be an electric design / testing engineer then.

Those that sorted out their confusion.


or someone that can read a manual

It's not covered in the manual.

Partly covered by not explained.

"Overheat protection" was the phrase, rather than cut-out or fuse .




or actually think,

So not you then, you have to ask here.

John Rumm gave some useful information and so did Roger Hayter, whereas you've just talked ****.



Many thanks for your email and my apologies for this error.
Our technical team have advised that they believed this to be faulty.

That's what they said to you dependant on what you told them.
you could have told them it burst into flames for all I know.



If you can advise of the order details for this order this can be
logged for you.

Kind regards,

CPC Sales team"

strange that the 'sales' team have replied or did you miss that bit.


whoever you said you contacted suggested they should be returned.

Nope:

"Hello,

Many thanks for your email and my apologies for this error.
Our technical team have advised that they believed this to be faulty.

If you can advise of the order details for this order this can be
logged for you.

Kind regards,

CPC Sales team"

So they won;t replacce a fualty heater that is under a years warrenty is that what yuo;re saying.



where as my productinfo said they are designe dto switch down to 700W..

Yes, so they say.

So for me there's no problem then,

Good for you ... so you will be happy to do the overnight coat test
yes?

No no more than yuo'll be happy to get in a car and run down peolpe walking across a bridge.


if they were designed to do that,

Ah, I think he's getting closer ... *IF*.

At least I have that ability that you lack.


some here suggested faulty wiring as tehy were meant to switch off.

Yes, me, all part of the same potential issue.

No issue at all now.

Unless you can tell me exaclt ywhat the 'potentail' issue is, but I'm betting yuo can't.

How much you willing to bet mate? £100?

make it £1000.


Oh, you have spoken to the manufacturers as well now have you?

I haven't spoken to anyone

You are a liar then (or so stupid you don't understand that an email
correspondence includes 'speaking to someone' in that context).

No it doesn't NOT in law.



(and neither have you so what are these potential issues you speak of)

I have (see above).

you've no idea.

The reason we have to be here while teh studetns are here is that afetr they leave we have to turn off the equipment and that has been done for the last 30+ years, we have to make sure all the students leave and that the lab is safe, we even used to switch ALL the power off and that was before we had these heaters.


but those at product info said.

-----------------------------------
"Unfortunately there was confusion over our initial response, the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat.

Yes, but a 'drop in power' isn't the same as 'turning all the elements
off in the light of an overheat condition' is it?

No who said it was.




So, when Vauxhall says 'There are no issues with your Zafira', you
will be happy to sit there when it is in flames around you'?

Our heaters weren't made by Vauxhall.
Are Zafira designed to put flames around you ?




Where it says.
"the drop in power drain is due to an internal thermostat designed to lower the temperature to ensure the radiator does not overheat"

I know, I told you that is was there and exactly what it did ... and
you argued many times that it even existed.

LIAR.


NO WHERE does it say the heater switches OFF.

I never said it did, just that I feel it would be safer if it did.

Who gives a **** what you think.



NO WHERE does it say the heater phones home or is a danger if it switches down to 700W

Grow up.

So where's the danger ?


So where do you get the idea that the heaters are faulty, it;s yuor head that;s faulty nothing else.

That's your call mate. Done the coat test yet?

Don't need to.

SO the potential issue is no longer a potential issue.

Yup, still is,

No it isn't.

Yes it is. That fact that you don't understand what it is doesn't stop
it existing.

The fact that your an idiot doesn't prove anything about the heaters.


as even a technical numbskull like you should be able
to see. Put the radiator on 700W

yuo can;t pu it on 700W ****wit.

Of course you can, you just flick the first switch on (really, are you
*that* stupid)???!!!

There isn't a switch for 700W ****wit the wattage depends on the input voltage.
You don;t even know the basics do you. There is NO setting for setting the number of watts just 3 heat settings, you can see that in the manual, no where does it say what wattage the switches represent.
At 202V the wattage is about 675W at other times it's over 720W it varies depending on the input voltage.



and the stat on full and chuck a big
coat over it and see what happens. If you are confident there are no
safety issues, leave it like that overnight.

Then stick your fingers in an electric light socket, then surely we should send all electric light sockets back shouldn't we.

Grow up. Do the test if you are so sure of yourself.

yuo're the one going on about potential issues they are potential issues with almost everything if you don't follow instructions.



What about the potential of peole runnjng oput in front of cars, are yuo saying send all the cars back for repair ?

Grow up.

Get a grip.

You are making yourself look more stupid than normal and just
digging yourself in deeper and deeper mate.

That's you claiming that things have potential issues if you misuse them makes you look like you don't know how to treat anything as it says in the manual do not cover do not use near or put in the bath.


Switch it to 700W, turn the thermostat up to full, chuck a big coat
over it and go home for the evening.

you dumb ****er, go and play with the traffic, go play chicken like the kid you are.


Then tell everyone they have to return their cars because of potential safety issues.

On Mon, 27 Nov 2017 09:02:08 -0800 (PST), whisky-dave
wrote:

snip dave throwing his toys out of the pram as it's obvious he's dug
himself in too deep he now can't get back out

'Yes dave, you are right and I am wrong.'

Right, if it was me, I would do the following tests, just OOI.

Switch the NoII / 1300W position on *only* with your current
measurement plug in place, and the main stat on full, see if it cuts
back to 700W or *at all* or after the ~2 hours you mentioned
previously.

If it still overtemps with just the high power element on, try it
again with just the low power element (NoI, 700W, it really shouldn't
with just that because 1) you said it doesn't anyway 2) the rad should
be able to dissipate 700W (when not covered)).

Cheers, T i m

On Monday, 27 November 2017 18:08:53 UTC, T i m wrote:
On Mon, 27 Nov 2017 09:02:08 -0800 (PST), whisky-dave
wrote:

snip dave throwing his toys out of the pram as it's obvious he's dug
himself in too deep he now can't get back out

yuo;re the one digging a hoe, for yourself.



'Yes dave, you are right and I am wrong.'

At last you've got it.


Right, if it was me, I would do the following tests, just OOI.
Luckily I;'m not you otherwose I'd be having sex with the radiator while it was on and burnt myself then I'd be able to claim it as a 'potentail issue' and would claim under H&S.


Switch the NoII / 1300W position on *only* with your current
measurement plug in place, and the main stat on full, see if it cuts
back to 700W or *at all* or after the ~2 hours you mentioned
previously.

and that would prove what exactly ?
I know that the overtemp protection which sets the heater back to 700W kicksm in whenn the fins of teh rad. reach about 98C and when it gets down to about 80C it goes back to the ~2KW or whatever you set.


If it still overtemps with just the high power element on, try it
again with just the low power element (NoI, 700W, it really shouldn't
with just that because 1) you said it doesn't anyway 2) the rad should
be able to dissipate 700W (when not covered)).

Yes I know and it does.


Cheers, T i m

On Tue, 28 Nov 2017 01:58:12 -0800 (PST), whisky-dave
wrote:

snip more of dave's bizarre ranting's


Switch the NoII / 1300W position on *only* with your current
measurement plug in place, and the main stat on full, see if it cuts
back to 700W or *at all* or after the ~2 hours you mentioned
previously.

and that would prove what exactly ?

That the radiator could *continuously* run on the larger element on
it's own and therefore possibly give off more actual heat than when
it's cycling between the 700W and 2kW (nominally).

At the end of the day, the trick would to be to keep the surface
temperature of the rad as close to the overtemp trip as possible but
without tripping.

I know that the overtemp protection which sets the heater back to 700W kicksm in whenn the fins of teh rad. reach about 98C and when it gets down to about 80C it goes back to the ~2KW or whatever you set.

I know. Remember, you don't have to remind me how it works because I
explained that to you. It would only go back to the ~2kW, not
'whatever you set' because the 700W element isn't protected by the
overtemp stat and wouldn't be switched in.

If you *just* have the larger element on and it still cycles on the
overtemp stat the wattage will go between ~1700 and 0.


If it still overtemps with just the high power element on, try it
again with just the low power element (NoI, 700W, it really shouldn't
with just that because 1) you said it doesn't anyway 2) the rad should
be able to dissipate 700W (when not covered)).

Yes I know and it does.

Just to be clear here ... you do know that it doesn't cycle on the
overtemp switch when just running the larger element on it's own?

Cheers, T i m

On Tuesday, 28 November 2017 10:41:11 UTC, T i m wrote:
On Tue, 28 Nov 2017 01:58:12 -0800 (PST), whisky-dave
wrote:


Switch the NoII / 1300W position on *only* with your current
measurement plug in place, and the main stat on full, see if it cuts
back to 700W or *at all* or after the ~2 hours you mentioned
previously.

and that would prove what exactly ?

That the radiator could *continuously* run on the larger element on
it's own and therefore possibly give off more actual heat than when
it's cycling between the 700W and 2kW (nominally).

No point in selecting 1300W when you want full 2KW heating.


At the end of the day, the trick would to be to keep the surface
temperature of the rad as close to the overtemp trip as possible but
without tripping.

No what we want is for it not to 'trip' as you call it.


I know that the overtemp protection which sets the heater back to 700W kicksm in whenn the fins of teh rad. reach about 98C and when it gets down to about 80C it goes back to the ~2KW or whatever you set.

I know. Remember, you don't have to remind me how it works because I
explained that to you.

No yuo were clueless.

It would only go back to the ~2kW, not
'whatever you set'

If you''d set it to 1300W it's go back to that.

because the 700W element isn't protected by the
overtemp stat and wouldn't be switched in.

So not much good then is it and I don't care whther or not the 700W is protected or not.




If you *just* have the larger element on and it still cycles on the
overtemp stat the wattage will go between ~1700 and 0.

The larger element i.e only elemnet II switched on you get ~1050W
So where rthe **** you're getting 1300W from I don't know.


If it still overtemps with just the high power element on, try it
again with just the low power element (NoI, 700W, it really shouldn't
with just that because 1) you said it doesn't anyway 2) the rad should
be able to dissipate 700W (when not covered)).

Yes I know and it does.

Just to be clear here ... you do know that it doesn't cycle on the
overtemp switch when just running the larger element on it's own?

I do NOT care.



Cheers, T i m

On Tue, 28 Nov 2017 04:28:55 -0800 (PST), whisky-dave
wrote:

On Tuesday, 28 November 2017 10:41:11 UTC, T i m wrote:
On Tue, 28 Nov 2017 01:58:12 -0800 (PST), whisky-dave
wrote:


Switch the NoII / 1300W position on *only* with your current
measurement plug in place, and the main stat on full, see if it cuts
back to 700W or *at all* or after the ~2 hours you mentioned
previously.

and that would prove what exactly ?

That the radiator could *continuously* run on the larger element on
it's own and therefore possibly give off more actual heat than when
it's cycling between the 700W and 2kW (nominally).

No point in selecting 1300W when you want full 2KW heating.

Except you aren't getting 2kW heating are you?


At the end of the day, the trick would to be to keep the surface
temperature of the rad as close to the overtemp trip as possible but
without tripping.

No what we want is for it not to 'trip' as you call it.

That's just what I said.


I know that the overtemp protection which sets the heater back to 700W kicksm in whenn the fins of teh rad. reach about 98C and when it gets down to about 80C it goes back to the ~2KW or whatever you set.

I know. Remember, you don't have to remind me how it works because I
explained that to you.

No yuo were clueless.

Oh the irony.


It would only go back to the ~2kW, not
'whatever you set'

If you''d set it to 1300W it's go back to that.

Exactly, not ~2kW then, as you said.

because the 700W element isn't protected by the
overtemp stat and wouldn't be switched in.

So not much good then is it and I don't care whther or not the 700W is protected or not.

Someone might if it caused a fire.


If you *just* have the larger element on and it still cycles on the
overtemp stat the wattage will go between ~1700 and 0.

The larger element i.e only elemnet II switched on you get ~1050W

No, *you* get that because of your substandard supply. 'Most people'
would get ~1300W (if it was plugged into a decent 240V supply).

So where rthe **** you're getting 1300W from I don't know.

Of course you don't. Further, it doesn't actually matter what the
actual values are, it is the principals we are talking here.


If it still overtemps with just the high power element on, try it
again with just the low power element (NoI, 700W, it really shouldn't
with just that because 1) you said it doesn't anyway 2) the rad should
be able to dissipate 700W (when not covered)).

Yes I know and it does.

Just to be clear here ... you do know that it doesn't cycle on the
overtemp switch when just running the larger element on it's own?

I do NOT care.

More like 'You do not know or understand', so I can leave you to your
ignorance then.

Cheers, T i m