On 15/05/2018 08:29, newshound wrote:
On 15/05/2018 07:57, Tricky Dicky wrote:
There appears to be two versions of the Comet Kiln, the ECO which
draws 3kW which should be fine using a 13A plug in a standard socket.
The other is a 5.5kW model for which a plug and socket is totally
inadequate. There should be a ratings plate somewhere on the kiln
check the wattage, although I would have thought your professional
electrician would have checked that first.

Richard

Good point.

The other thing I would suggest even for the 3 kW model is to get your
sparks to fit a "cooker" type breaker switch and then an industrial type
plug and socket like this:

https://uk.rs-online.com/web/p/produ...E&gclsrc=aw.ds


(This is what I did in a friend's business unit after he was getting
short life even from MK plugs and sockets that were running with a high
duty factor).


A 16 Amp plug and socket isn't sufficient to provide 5.5kW

Can I suggest you fix your signature and use 2 hyphens '--'
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On Tue, 15 May 2018 20:33:29 +0100, Fredxx wrote:

Can I suggest you fix your signature and use 2 hyphens '--'

Or even better, the correct 'two hyphens and a space'.

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In article ,
Terry Casey wrote:
Heating of a connector happens because of resistance. The same resistance
will result in more heat with more current.

The contact spring tension has to be a compremise between
insertion force versus contact force so why can't someone
devise a switched 13A socket which uses a cam arrangement to
increase the contact force, reducing resistance, when the
switch is moved to the on position?

And of course brass oxidises. I'd guess the contact resistance goes up
where a plug is left in a socket for a long time.

(Personally, I prefer unswitched sockets but even when you
find them these days, they are more expensive than the
switched version!)

Wouldn't suit me in my kitchen - and elswhere. Have a few things which I
leave in position, but switch off at the socket. Unplugging would look
less tidy.

--
*Why do the two "sanction"s (noun and verb) mean opposites?*

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
says...

In article ,
Terry Casey wrote:


(Personally, I prefer unswitched sockets but even when you
find them these days, they are more expensive than the
switched version!)

Wouldn't suit me in my kitchen - and elswhere. Have a few things which I
leave in position, but switch off at the socket. Unplugging would look
less tidy.

I'm not suggesting getting rid of them, just that in a lot of
cases the switch is never used so fitting the unswitched
variety in these positions would stop anybody turning them off
by accident.

Sorry if I've already told this tale before but I went to work
on a 22 channel cable TV system at the London Stock Ecchange
in 1969. Due mainly to the old GPO monopoly - but also because
they had ducts all over the city - they provided the main
trunk with the Stock Exchange providing the local distribution
within the individual buildings.

The GPO trunk terminated in the basement and was powered from
an unmetered feed via a switched spur. When I arrived on the
scene the network was still being commissioned and because of
the difficulties of parking, the GPO guys, like us, worked on
foot and the only level measuring set accurate enough for the
job was damned heavy!

Once or twice a week, they would pick up where they'd finished
up the previous day and found no signals! There were, of
course, no subcribers at the time, so we didn't get phone
calls to help pin down the source of the problem so they would
trudge back along the trunk checking from building to building
until they found the cause of the problem - someone had
switched off the power!

I don't know about now but in those days most large buildings
had a Housekeeper, usually with a flat on the top floor and,
out of hours, he would make a routine security check. Sooner
or later, he would spot the neon on the spur, to his mind
wasting electricity at that time of night and switch it off!

Eventually the Stock Exchange sent its own electricians to
every building to swap out the switched spur for an unswitched
one ...


--

Terry

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On Tue, 15 May 2018 11:17:30 +0100
"Dave Plowman (News)" wrote:

In article ,
Lea Goldberg m
wrote:
.so,for the first 2 years,my comet kiln worked perfectly...then the
socket burnt out,replaced it(always ised a professional
electrician)thos time,socket switches got hardrr and harder to
switch on,then the socket stopped working again,replaced the whole
unit...now its happened again...the socket is about 20 ft via
armoured cable to the house,the kiln room isnt damp...the kilns
fine,but the plug gets a bit hot(when it worked)the electrician
seems to be baffled...'must be your kiln'...but i know nothing
about electrics so cant argue the toss!can ANYONE help...its
driving me mad....

Despite being rated at 13 amps, most sockets and plugs aren't happy to
carry that for very long periods. They are a domestic connector and
really for intermittent use at full capacity. As with a kettle or
washing machine etc. Hence things like 13 amp water heaters normally
not plugged in, but hard wired. Same sort of thing with storage rads.

Even more so if cooling to the socket/plug is restricted in any way.

The answer is to go for an industrial 16 amp plug and socket - if
indeed it has to have a plug/socket arrangement.


I have idly wondered why MCB spurs don't seem to be available. 3A, 10,
13A and 16A MCB spurs would be quite useful and there would be no chance
of someone putting the wrong rating of fuse in them.

In article ,
Jim wrote:
On Tue, 15 May 2018 11:17:30 +0100
"Dave Plowman (News)" wrote:

In article ,
Lea Goldberg m
wrote:
.so,for the first 2 years,my comet kiln worked perfectly...then the
socket burnt out,replaced it(always ised a professional
electrician)thos time,socket switches got hardrr and harder to
switch on,then the socket stopped working again,replaced the whole
unit...now its happened again...the socket is about 20 ft via
armoured cable to the house,the kiln room isnt damp...the kilns
fine,but the plug gets a bit hot(when it worked)the electrician
seems to be baffled...'must be your kiln'...but i know nothing
about electrics so cant argue the toss!can ANYONE help...its
driving me mad....

Despite being rated at 13 amps, most sockets and plugs aren't happy to
carry that for very long periods. They are a domestic connector and
really for intermittent use at full capacity. As with a kettle or
washing machine etc. Hence things like 13 amp water heaters normally
not plugged in, but hard wired. Same sort of thing with storage rads.

Even more so if cooling to the socket/plug is restricted in any way.

The answer is to go for an industrial 16 amp plug and socket - if
indeed it has to have a plug/socket arrangement.


I have idly wondered why MCB spurs don't seem to be available. 3A, 10,
13A and 16A MCB spurs would be quite useful and there would be no chance
of someone putting the wrong rating of fuse in them.


probably because there's already an MCB on the distribution board. I don't
think it's very good practice to have MCBs in series - but someone will
probably say it's fine.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On Wed, 16 May 2018 20:46:11 +0100
charles wrote:

In article ,
Jim wrote:
On Tue, 15 May 2018 11:17:30 +0100
"Dave Plowman (News)" wrote:

In article ,
Lea Goldberg
m wrote:
.so,for the first 2 years,my comet kiln worked perfectly...then
the socket burnt out,replaced it(always ised a professional
electrician)thos time,socket switches got hardrr and harder to
switch on,then the socket stopped working again,replaced the
whole unit...now its happened again...the socket is about 20 ft
via armoured cable to the house,the kiln room isnt damp...the
kilns fine,but the plug gets a bit hot(when it worked)the
electrician seems to be baffled...'must be your kiln'...but i
know nothing about electrics so cant argue the toss!can ANYONE
help...its driving me mad....

Despite being rated at 13 amps, most sockets and plugs aren't
happy to carry that for very long periods. They are a domestic
connector and really for intermittent use at full capacity. As
with a kettle or washing machine etc. Hence things like 13 amp
water heaters normally not plugged in, but hard wired. Same sort
of thing with storage rads.

Even more so if cooling to the socket/plug is restricted in any
way.

The answer is to go for an industrial 16 amp plug and socket - if
indeed it has to have a plug/socket arrangement.


I have idly wondered why MCB spurs don't seem to be available. 3A,
10, 13A and 16A MCB spurs would be quite useful and there would be
no chance of someone putting the wrong rating of fuse in them.


probably because there's already an MCB on the distribution board. I
don't think it's very good practice to have MCBs in series - but
someone will probably say it's fine.


Happens all the time. From a fused sub main to another CU, for instance.

On Wed, 16 May 2018 18:56:33 +0100, Terry Casey wrote:

I don't know about now but in those days most large buildings had a
Housekeeper, usually with a flat on the top floor and, out of hours, he
would make a routine security check. Sooner or later, he would spot the
neon on the spur, to his mind wasting electricity at that time of night
and switch it off!

Eventually the Stock Exchange sent its own electricians to every
building to swap out the switched spur for an unswitched one ...

We had this problem at home on a much more limited basis.

My M-I-L lived with us for about two years before she died from vascular
dementia. Being of the age she was (94) she was meticulous about turning
everything off.

One thing was the kettle, which has a base unit that we leave plugged in
and switched on at the socket. We'd get up, fill the kettle, push the
button and then come back to find cold water. All of the phones need a
mains supply (IP phones) and she turned those off too. Plus, on one
occasion, the central heating spur beside the boiler.

It was sufficient (to my amazement) to put stickers on each plug/spur
saying "DO NOT TURN OFF" - these were red and white ones from CPC and
looked 'official' so she did what they told her.

On a related note, she did not like taking pills. When she died, we found
a hoard of boxes of pills. However, for the last few months she was
bedridden and we gave her the medication (not easy anyway as her hands
shook and she dropped the pills). The solution to that (my idea) turned
out to be using the little plastic 'cup' things they use for medication
is hospitals. These were 'official' so she took the pills - and it was
also harder to drop them as the cup was easier to grip. The cups were
easy to get on eBay!



--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

In article ,
Jim wrote:
On Wed, 16 May 2018 20:46:11 +0100
charles wrote:

In article ,
Jim wrote:
On Tue, 15 May 2018 11:17:30 +0100
"Dave Plowman (News)" wrote:

In article ,
Lea Goldberg
m wrote:
.so,for the first 2 years,my comet kiln worked perfectly...then
the socket burnt out,replaced it(always ised a professional
electrician)thos time,socket switches got hardrr and harder to
switch on,then the socket stopped working again,replaced the
whole unit...now its happened again...the socket is about 20 ft
via armoured cable to the house,the kiln room isnt damp...the
kilns fine,but the plug gets a bit hot(when it worked)the
electrician seems to be baffled...'must be your kiln'...but i
know nothing about electrics so cant argue the toss!can ANYONE
help...its driving me mad....

Despite being rated at 13 amps, most sockets and plugs aren't
happy to carry that for very long periods. They are a domestic
connector and really for intermittent use at full capacity. As
with a kettle or washing machine etc. Hence things like 13 amp
water heaters normally not plugged in, but hard wired. Same sort
of thing with storage rads.

Even more so if cooling to the socket/plug is restricted in any
way.

The answer is to go for an industrial 16 amp plug and socket - if
indeed it has to have a plug/socket arrangement.


I have idly wondered why MCB spurs don't seem to be available. 3A,
10, 13A and 16A MCB spurs would be quite useful and there would be
no chance of someone putting the wrong rating of fuse in them.


probably because there's already an MCB on the distribution board. I
don't think it's very good practice to have MCBs in series - but
someone will probably say it's fine.


Happens all the time. From a fused sub main to another CU, for instance.


but a "FUSED" Sub-main doesn't involve an MCB

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On Wed, 16 May 2018 21:35:47 +0100
charles wrote:

In article ,
Jim wrote:
On Wed, 16 May 2018 20:46:11 +0100
charles wrote:

In article ,
Jim wrote:
On Tue, 15 May 2018 11:17:30 +0100
"Dave Plowman (News)" wrote:

In article ,
Lea Goldberg
m
wrote:
.so,for the first 2 years,my comet kiln worked
perfectly...then the socket burnt out,replaced it(always
ised a professional electrician)thos time,socket switches
got hardrr and harder to switch on,then the socket stopped
working again,replaced the whole unit...now its happened
again...the socket is about 20 ft via armoured cable to the
house,the kiln room isnt damp...the kilns fine,but the plug
gets a bit hot(when it worked)the electrician seems to be
baffled...'must be your kiln'...but i know nothing about
electrics so cant argue the toss!can ANYONE help...its
driving me mad....

Despite being rated at 13 amps, most sockets and plugs aren't
happy to carry that for very long periods. They are a domestic
connector and really for intermittent use at full capacity. As
with a kettle or washing machine etc. Hence things like 13 amp
water heaters normally not plugged in, but hard wired. Same
sort of thing with storage rads.

Even more so if cooling to the socket/plug is restricted in
any way.

The answer is to go for an industrial 16 amp plug and socket
- if indeed it has to have a plug/socket arrangement.


I have idly wondered why MCB spurs don't seem to be available.
3A, 10, 13A and 16A MCB spurs would be quite useful and there
would be no chance of someone putting the wrong rating of fuse
in them.


probably because there's already an MCB on the distribution
board. I don't think it's very good practice to have MCBs in
series - but someone will probably say it's fine.


Happens all the time. From a fused sub main to another CU, for
instance.


but a "FUSED" Sub-main doesn't involve an MCB


Jesus!

OK, an MCB protected sub main. Happy?

On Wednesday, 16 May 2018 21:46:22 UTC+1, Jim wrote:
On Wed, 16 May 2018 21:35:47 +0100

but a "FUSED" Sub-main doesn't involve an MCB


Jesus!

OK, an MCB protected sub main. Happy?

Jesus doesn't involve an MCB either