Folks,

My hobby room has a 1Kw underfloor heating element, connected to a
dedicated off-peak circuit. Most of the time this is adequate but
during extended cold spells it's really not sufficient for my old bones.

Accordingly, I've just taken delivery of a new oil-filled radiator
(DeLonghi V550920) intending to connect it to the off-peak circuit's
3-pin socket - previously used, I believe, for a standalone storage
heater - to take advantage of the 2 hour 'boost' available between
12:00 and 14:00.

Unfortunately, when reading through the instructions, I came across
this paragraph:

"Caution: In order to avoid a hazard due to inadvertent resetting of
the thermal cutout, this appliance must not be supplied through an
external switching device such as a timer, or connected to a circuit
that is regularly switched on and off by the utility."


In the real world, I'd have thought plenty of people would be turning
this sort of device on and off by plugging/unplugging it or using the
wall socket's switch - and I can't see how this would be any different
from turning it on and off via a timer or an off-peak circuit.

Can anyone help me to understand what's going on here, please? Is there
really some material reason why turning the device off and on "at the
mains" is a no-no?


Thanks,
Peter

On Fri, 09 Jan 2015 17:22:43 +0000, Neddie Seagoon wrote:

My hobby room has a 1Kw underfloor heating element, connected to a
dedicated off-peak circuit. Most of the time this is adequate but during
extended cold spells it's really not sufficient for my old bones.

I take it that it's not a very big room? The normal recommendation is
100-200w/m2.

Accordingly, I've just taken delivery of a new oil-filled radiator
(DeLonghi V550920) intending to connect it to the off-peak circuit's
3-pin socket - previously used, I believe, for a standalone storage
heater - to take advantage of the 2 hour 'boost' available between 12:00
and 14:00.

Unfortunately, when reading through the instructions, I came across this
paragraph:

"Caution: In order to avoid a hazard due to inadvertent resetting of the
thermal cutout, this appliance must not be supplied through an external
switching device such as a timer, or connected to a circuit that is
regularly switched on and off by the utility."

In the real world, I'd have thought plenty of people would be turning
this sort of device on and off by plugging/unplugging it or using the
wall socket's switch - and I can't see how this would be any different
from turning it on and off via a timer or an off-peak circuit.

No, it's pretty much the same thing.

Can anyone help me to understand what's going on here, please? Is there
really some material reason why turning the device off and on "at the
mains" is a no-no?

Going on the wording, I'd guess that if the thermal cutout trips, power
is still required to maintain it tripped until a set period of time
expires. If it's switched off, the trip would reset. If it's switched off-
and-on, it may well then return to heating before the trip should be
reset. Repeat that repeatedly, and there is a very faintly slim chance
that it may eventually overheat sufficiently for the oil to ignite,
killing every single nun carrying a basket of kittens within a ten mile
radius.

Meanwhile, here in the real world and with a modicum of sanity on the
part of the user...

On Friday, January 9, 2015 at 5:22:46 PM UTC, Neddie Seagoon wrote:
Folks,

My hobby room has a 1Kw underfloor heating element, connected to a
dedicated off-peak circuit. Most of the time this is adequate but
during extended cold spells it's really not sufficient for my old bones.

Accordingly, I've just taken delivery of a new oil-filled radiator
(DeLonghi V550920) intending to connect it to the off-peak circuit's
3-pin socket - previously used, I believe, for a standalone storage
heater - to take advantage of the 2 hour 'boost' available between
12:00 and 14:00.

Unfortunately, when reading through the instructions, I came across
this paragraph:

"Caution: In order to avoid a hazard due to inadvertent resetting of
the thermal cutout, this appliance must not be supplied through an
external switching device such as a timer, or connected to a circuit
that is regularly switched on and off by the utility."


In the real world, I'd have thought plenty of people would be turning
this sort of device on and off by plugging/unplugging it or using the
wall socket's switch - and I can't see how this would be any different
from turning it on and off via a timer or an off-peak circuit.

Can anyone help me to understand what's going on here, please? Is there
really some material reason why turning the device off and on "at the
mains" is a no-no?


Thanks,
Peter

Sounds like a nonissue on the face of it. Its a bit like the handtools that advise using a mask & goggles, even on needlenose pliers.


NT

On 09/01/15 17:22, Neddie Seagoon wrote:

Can anyone help me to understand what's going on here, please? Is there
really some material reason why turning the device off and on "at the
mains" is a no-no?


Sounds like utter and complete cock to me.

I have that exact model (3 in fact plus the Dragon) - or at least the
one that looks exactly like it from 3 years ago.

I've been remote switching mine for years - socket timer then ZWave
without issue.

In fact, unless it has an inbuilt electronic controller (it doesn't)
normal right thinking people would expect to do this.

I honestly do not know what they are on about. It has a thermostat and
(hopefully) and internal overheat cutout.

Given there is no reset button (at least not externally) I assume it is
either a non resettable cutout or self resetting.

If it is self resetting, I fail to see the problem - it will be a
thermo-mechanical device, it's not likely to be something that would
magically reset when the mains goes away.

In which case it will reset when the heater cools down a bit and power
up again anyway.

Unless they've done something very stupid in the design.

On 09/01/15 17:31, Adrian wrote:

Going on the wording, I'd guess that if the thermal cutout trips, power
is still required to maintain it tripped until a set period of time
expires. If it's switched off, the trip would reset.


I would give that the engineering rating of "a ****ing stupid design" -
criminal even. Manual reset or bimetallic with a very large hysteresis
would be sensible.

But even so, the trip should trip again if it's too hot?

On 09/01/2015 18:20, Tim Watts wrote:
On 09/01/15 17:22, Neddie Seagoon wrote:

Can anyone help me to understand what's going on here, please? Is there
really some material reason why turning the device off and on "at the
mains" is a no-no?


Sounds like utter and complete cock to me.

I have that exact model (3 in fact plus the Dragon) - or at least the
one that looks exactly like it from 3 years ago.

I've been remote switching mine for years - socket timer then ZWave
without issue.

In fact, unless it has an inbuilt electronic controller (it doesn't)
normal right thinking people would expect to do this.

I honestly do not know what they are on about. It has a thermostat and
(hopefully) and internal overheat cutout.

Given there is no reset button (at least not externally) I assume it is
either a non resettable cutout or self resetting.

If it is self resetting, I fail to see the problem - it will be a
thermo-mechanical device, it's not likely to be something that would
magically reset when the mains goes away.

In which case it will reset when the heater cools down a bit and power
up again anyway.

Unless they've done something very stupid in the design.

+1

On Friday, January 9, 2015 at 6:21:04 PM UTC, Tim Watts wrote:
On 09/01/15 17:22, Neddie Seagoon wrote:

Can anyone help me to understand what's going on here, please? Is there
really some material reason why turning the device off and on "at the
mains" is a no-no?


Sounds like utter and complete cock to me.

I have that exact model (3 in fact plus the Dragon) - or at least the
one that looks exactly like it from 3 years ago.

I've been remote switching mine for years - socket timer then ZWave
without issue.

In fact, unless it has an inbuilt electronic controller (it doesn't)
normal right thinking people would expect to do this.

I honestly do not know what they are on about. It has a thermostat and
(hopefully) and internal overheat cutout.

Given there is no reset button (at least not externally) I assume it is
either a non resettable cutout or self resetting.

If it is self resetting, I fail to see the problem - it will be a
thermo-mechanical device, it's not likely to be something that would
magically reset when the mains goes away.

In which case it will reset when the heater cools down a bit and power
up again anyway.

Unless they've done something very stupid in the design.

The cutout may be a thermistor. It may only survive so many cycles. If it fails unsafely with the heater overheating, it will overheat. Which in an oil rad is not the end of the world.


NT

On 09/01/15 22:57, wrote:

The cutout may be a thermistor. It may only survive so many cycles.
If it fails unsafely with the heater overheating, it will overheat.
Which in an oil rad is not the end of the world.

It would seem an odd choice.

Personally I would use a manually resettable thermal trip - the user
knows it's tripped and will hopefully rememdy the problem (like a coat
fell on it).

If it were me, being me, I would also put a thermal fuse set to perhaps
80C as the ultimate and very reliable failsafe.

the OP has me intrigued - I should have the cover off mine and see
what's actually in there... Then we can settle this...

Tomorrow if it looks straightforward.

On 09/01/2015 23:09, Tim Watts wrote:
On 09/01/15 22:57, wrote:

The cutout may be a thermistor. It may only survive so many cycles.
If it fails unsafely with the heater overheating, it will overheat.
Which in an oil rad is not the end of the world.

It would seem an odd choice.

Personally I would use a manually resettable thermal trip - the user
knows it's tripped and will hopefully rememdy the problem (like a coat
fell on it).

As oil filled rads should cope with having a coat accidently thrown over
them without tripping I think more investigation would be needed and a
new limit stat probably required. Its the limit stat that keeps the
surface from becoming dangerously hot and the thermal fuse that provides
backup for if the limit stat fails.

On Saturday, January 10, 2015 at 8:27:52 AM UTC, Dennis@home wrote:
On 09/01/2015 23:09, Tim Watts wrote:
On 09/01/15 22:57, wrote:

The cutout may be a thermistor. It may only survive so many cycles.
If it fails unsafely with the heater overheating, it will overheat.
Which in an oil rad is not the end of the world.

It would seem an odd choice.

Personally I would use a manually resettable thermal trip - the user
knows it's tripped and will hopefully rememdy the problem (like a coat
fell on it).

As oil filled rads should cope with having a coat accidently thrown over
them without tripping I think more investigation would be needed and a
new limit stat probably required. Its the limit stat that keeps the
surface from becoming dangerously hot and the thermal fuse that provides
backup for if the limit stat fails.

no, its the choice of heater power versus area that limits surface temp.

Engineers often do what's cheapest, a thermistor is cheaper than a manually resettable bimetal.


NT

On 10/01/15 09:02, wrote:
On Saturday, January 10, 2015 at 8:27:52 AM UTC, Dennis@home wrote:
On 09/01/2015 23:09, Tim Watts wrote:
On 09/01/15 22:57, wrote:

The cutout may be a thermistor. It may only survive so many cycles.
If it fails unsafely with the heater overheating, it will overheat.
Which in an oil rad is not the end of the world.

It would seem an odd choice.

Personally I would use a manually resettable thermal trip - the user
knows it's tripped and will hopefully rememdy the problem (like a coat
fell on it).

As oil filled rads should cope with having a coat accidently thrown over
them without tripping I think more investigation would be needed and a
new limit stat probably required. Its the limit stat that keeps the
surface from becoming dangerously hot and the thermal fuse that provides
backup for if the limit stat fails.

no, its the choice of heater power versus area that limits surface temp.

Engineers often do what's cheapest, a thermistor is cheaper than a manually resettable bimetal.

Except these are not "cheap" heaters - and I would expect DeLonghi not
top be skimping on safety devices, especially ones that cause problems
when operating heaters remotely which is waht half the users can be
expected to do...

On Saturday, January 10, 2015 at 9:21:25 AM UTC, Tim Watts wrote:
On 10/01/15 09:02, wrote:
On Saturday, January 10, 2015 at 8:27:52 AM UTC, Dennis@home wrote:
On 09/01/2015 23:09, Tim Watts wrote:
On 09/01/15 22:57, wrote:

The cutout may be a thermistor. It may only survive so many cycles.
If it fails unsafely with the heater overheating, it will overheat.
Which in an oil rad is not the end of the world.

It would seem an odd choice.

Personally I would use a manually resettable thermal trip - the user
knows it's tripped and will hopefully rememdy the problem (like a coat
fell on it).

As oil filled rads should cope with having a coat accidently thrown over
them without tripping I think more investigation would be needed and a
new limit stat probably required. Its the limit stat that keeps the
surface from becoming dangerously hot and the thermal fuse that provides
backup for if the limit stat fails.

no, its the choice of heater power versus area that limits surface temp.

Engineers often do what's cheapest, a thermistor is cheaper than a manually resettable bimetal.

Except these are not "cheap" heaters

so what

- and I would expect DeLonghi not
top be skimping on safety devices, especially ones that cause problems
when operating heaters remotely which is waht half the users can be
expected to do...

ah, assumptions


NT

On 2015-01-09 23:09:00 +0000, Tim Watts said:

On 09/01/15 22:57, wrote:
snip

the OP has me intrigued - I should have the cover off mine and see
what's actually in there... Then we can settle this...

Tomorrow if it looks straightforward.


Thanks to everyone for the comforting 'commonsense' replies.

The outcome of your delvings will be most interesting Tim...


Regards
Peter

On 10/01/15 10:02, wrote:
On Saturday, January 10, 2015 at 9:21:25 AM UTC, Tim Watts wrote:
On 10/01/15 09:02, wrote:
On Saturday, January 10, 2015 at 8:27:52 AM UTC, Dennis@home wrote:
On 09/01/2015 23:09, Tim Watts wrote:
On 09/01/15 22:57, wrote:

The cutout may be a thermistor. It may only survive so many cycles.
If it fails unsafely with the heater overheating, it will overheat.
Which in an oil rad is not the end of the world.

It would seem an odd choice.

Personally I would use a manually resettable thermal trip - the user
knows it's tripped and will hopefully rememdy the problem (like a coat
fell on it).

As oil filled rads should cope with having a coat accidently thrown over
them without tripping I think more investigation would be needed and a
new limit stat probably required. Its the limit stat that keeps the
surface from becoming dangerously hot and the thermal fuse that provides
backup for if the limit stat fails.

no, its the choice of heater power versus area that limits surface temp.

Engineers often do what's cheapest, a thermistor is cheaper than a manually resettable bimetal.

Except these are not "cheap" heaters

so what

So I don't expect them to be penny pinching with safety devices!


- and I would expect DeLonghi not
top be skimping on safety devices, especially ones that cause problems
when operating heaters remotely which is waht half the users can be
expected to do...

ah, assumptions



Not really - the rest of the heater has well made components.
NT

On 10/01/15 15:20, Tim Watts wrote:
On 10/01/15 10:02, wrote:
ah, assumptions

OK - enough of the assumption ********...

I just took mine apart. Here's the Flickr Album:

https://www.flickr.com/photos/timjwa...7650209754522/

Usual bimetallic air stat, switch (it's dual element, each is around 1kW
so positions 1 and 2 are the same output power, 3 is both so full power)

Here's the overheat device:

Pressed against the side of the rad with a leaf spring (cover slightly
undone, viewed from the side):

https://www.flickr.com/photos/timjwa...7650209754522/


And closer:


https://www.flickr.com/photos/timjwa...7650209754522/

(silver thing)


and removed, close up for the part number:

https://www.flickr.com/photos/timjwa...48955/sizes/o/


Googling finds:

http://www.sensata.com/download/1nt.pdf

which is a Sensata Klixon[1] Fixed Temperature Thermostat

[1]

Klixon is on the base:

https://www.flickr.com/photos/timjwa...57650209754522


Indeed - that little plastic tab out the back moves - so I guess is the
reset button.




Now, there are a number of reset (or not) options.


The weird thing is I read the part number as 1NT08L which is described
as "1NT08 Manual Reset / Silver Contacts" which agrees with what I think
it should be.

However, the case style is wrong (page 2 PDF)

It looks more like a 1NT02 series - as the terminals come off at 45 degrees.

Can anyone have a look at the photo and check - the "8" is a bit damaged
so it might be another digit.


The rest of the code decodes thus:

L - Limit switch (ie NC contacts)
5841 - Customer specific code
L180 - Limit, 180 (F or C?? code is missing)
MR - Manual Reset

240V@16A max, 10 cycles max


So I think it's reasonable to deduce that it is set to 180 Fahrenheit,
and is definitely a manual reset trip which is simple and mechanical
(bimetallic disc).


I'm also happy to say I think the construction is good quality and is
serviceable - parts are all on spade connectors. Looks like something
built to 1970s british standards.


So this brings us back to the original statement re external switching.
I am happy to declare, without hesitation "cobblers".

Does anyone wish to add to that, or disagree?

On 10/01/2015 16:33, Tim Watts wrote:
On 10/01/15 15:20, Tim Watts wrote:
On 10/01/15 10:02, wrote:
ah, assumptions

OK - enough of the assumption ********...

I just took mine apart. Here's the Flickr Album:

https://www.flickr.com/photos/timjwa...7650209754522/

Usual bimetallic air stat, switch (it's dual element, each is around 1kW
so positions 1 and 2 are the same output power, 3 is both so full power)

Here's the overheat device:

Pressed against the side of the rad with a leaf spring (cover slightly
undone, viewed from the side):

https://www.flickr.com/photos/timjwa...7650209754522/


And closer:


https://www.flickr.com/photos/timjwa...7650209754522/

(silver thing)


and removed, close up for the part number:

https://www.flickr.com/photos/timjwa...48955/sizes/o/


Googling finds:

http://www.sensata.com/download/1nt.pdf

which is a Sensata Klixon[1] Fixed Temperature Thermostat

[1]

Klixon is on the base:

https://www.flickr.com/photos/timjwa...57650209754522



Indeed - that little plastic tab out the back moves - so I guess is the
reset button.




Now, there are a number of reset (or not) options.


The weird thing is I read the part number as 1NT08L which is described
as "1NT08 Manual Reset / Silver Contacts" which agrees with what I think
it should be.

However, the case style is wrong (page 2 PDF)

It looks more like a 1NT02 series - as the terminals come off at 45
degrees.

Can anyone have a look at the photo and check - the "8" is a bit damaged
so it might be another digit.


The rest of the code decodes thus:

L - Limit switch (ie NC contacts)
5841 - Customer specific code
L180 - Limit, 180 (F or C?? code is missing)
MR - Manual Reset

240V@16A max, 10 cycles max


So I think it's reasonable to deduce that it is set to 180 Fahrenheit,
and is definitely a manual reset trip which is simple and mechanical
(bimetallic disc).


I'm also happy to say I think the construction is good quality and is
serviceable - parts are all on spade connectors. Looks like something
built to 1970s british standards.


So this brings us back to the original statement re external switching.
I am happy to declare, without hesitation "cobblers".

Does anyone wish to add to that, or disagree?

Perhaps some of the manufacturer's fancier models with electronic
controls implement some safety features in software? Those might need
such a warning in the manual, and perhaps the warning has been copied
and pasted into the manuals of other models just in case?

As a minor point, I think the component in your heater is rated at 10000
cycles rather than 10. That's reassuring for me, because the themal
cut-out in the poorly designed no-name oil-filled heater I use operates
frequently.

On 10/01/15 17:33, LumpHammer wrote:

Perhaps some of the manufacturer's fancier models with electronic
controls implement some safety features in software? Those might need
such a warning in the manual, and perhaps the warning has been copied
and pasted into the manuals of other models just in case?

It does make you wonder - people often swear manufacturer's instructions
are sacrosact - but half the time I wonder if they even proof read them!

As a minor point, I think the component in your heater is rated at 10000
cycles rather than 10. That's reassuring for me, because the themal
cut-out in the poorly designed no-name oil-filled heater I use operates
frequently.

Quite right - I see, reading again, it says "X 1000 cycles".

wrote in message
...
On Saturday, January 10, 2015 at 9:21:25 AM UTC, Tim Watts wrote:
On 10/01/15 09:02, wrote:
On Saturday, January 10, 2015 at 8:27:52 AM UTC, Dennis@home wrote:
On 09/01/2015 23:09, Tim Watts wrote:
On 09/01/15 22:57, wrote:

The cutout may be a thermistor. It may only survive so many cycles.
If it fails unsafely with the heater overheating, it will overheat.
Which in an oil rad is not the end of the world.

It would seem an odd choice.

Personally I would use a manually resettable thermal trip - the user
knows it's tripped and will hopefully rememdy the problem (like a
coat
fell on it).

As oil filled rads should cope with having a coat accidently thrown
over
them without tripping I think more investigation would be needed and a
new limit stat probably required. Its the limit stat that keeps the
surface from becoming dangerously hot and the thermal fuse that
provides
backup for if the limit stat fails.

no, its the choice of heater power versus area that limits surface
temp.

Engineers often do what's cheapest, a thermistor is cheaper than a
manually resettable bimetal.

Except these are not "cheap" heaters

so what

So you might expect them to not go for something
cheap that might not last as long if its used with a
time switch after its got a fault that the cutout is
protecting against.

On the other hand, they might well decide that
the advantages of automatically resetting rather
than manual resetting is worth it given that the
fault should be rare, like say someone putting
a rug on the heater to dry it and that tripping
the cutout when it gets too hot and its unlikely
that someone would do that and leave it on
a timer for weeks etc.

- and I would expect DeLonghi not top be skimping
on safety devices, especially ones that cause problems
when operating heaters remotely which is waht half
the users can be expected to do...

ah, assumptions

Not assumptions so much as a reasonable expectation.

On Saturday, January 10, 2015 at 6:47:44 PM UTC, Rod Speed wrote:
wrote in message
...
On Saturday, January 10, 2015 at 9:21:25 AM UTC, Tim Watts wrote:
On 10/01/15 09:02, wrote:
On Saturday, January 10, 2015 at 8:27:52 AM UTC, Dennis@home wrote:
On 09/01/2015 23:09, Tim Watts wrote:
On 09/01/15 22:57, wrote:

Engineers often do what's cheapest, a thermistor is cheaper than a
manually resettable bimetal.

Except these are not "cheap" heaters

so what

So you might expect them to not go for something
cheap that might not last as long if its used with a
time switch after its got a fault that the cutout is
protecting against.

On the other hand, they might well decide that
the advantages of automatically resetting rather
than manual resetting is worth it given that the
fault should be rare, like say someone putting
a rug on the heater to dry it and that tripping
the cutout when it gets too hot and its unlikely
that someone would do that and leave it on
a timer for weeks etc.

- and I would expect DeLonghi not top be skimping
on safety devices, especially ones that cause problems
when operating heaters remotely which is waht half
the users can be expected to do...

ah, assumptions

Not assumptions so much as a reasonable expectation.

Its normal practice to go cheap on some parts while promoting a device as of the highest quality etc. Its business as normal in the world of electricals/electronics. Yes many end users have their head in the adverts, but that's the reality.


NT

On Saturday, January 10, 2015 at 5:33:36 PM UTC, LumpHammer wrote:
On 10/01/2015 16:33, Tim Watts wrote:
On 10/01/15 15:20, Tim Watts wrote:
On 10/01/15 10:02, wrote:
ah, assumptions

OK - enough of the assumption ********...

I just took mine apart. Here's the Flickr Album:

https://www.flickr.com/photos/timjwa...7650209754522/

Usual bimetallic air stat, switch (it's dual element, each is around 1kW
so positions 1 and 2 are the same output power, 3 is both so full power)

Here's the overheat device:

Pressed against the side of the rad with a leaf spring (cover slightly
undone, viewed from the side):

https://www.flickr.com/photos/timjwa...7650209754522/


And closer:


https://www.flickr.com/photos/timjwa...7650209754522/

(silver thing)


and removed, close up for the part number:

https://www.flickr.com/photos/timjwa...48955/sizes/o/


Googling finds:

http://www.sensata.com/download/1nt.pdf

which is a Sensata Klixon[1] Fixed Temperature Thermostat

[1]

Klixon is on the base:

https://www.flickr.com/photos/timjwa...57650209754522



Indeed - that little plastic tab out the back moves - so I guess is the
reset button.




Now, there are a number of reset (or not) options.


The weird thing is I read the part number as 1NT08L which is described
as "1NT08 Manual Reset / Silver Contacts" which agrees with what I think
it should be.

However, the case style is wrong (page 2 PDF)

It looks more like a 1NT02 series - as the terminals come off at 45
degrees.

Can anyone have a look at the photo and check - the "8" is a bit damaged
so it might be another digit.


The rest of the code decodes thus:

L - Limit switch (ie NC contacts)
5841 - Customer specific code
L180 - Limit, 180 (F or C?? code is missing)
MR - Manual Reset

240V@16A max, 10 cycles max


So I think it's reasonable to deduce that it is set to 180 Fahrenheit,
and is definitely a manual reset trip which is simple and mechanical
(bimetallic disc).


I'm also happy to say I think the construction is good quality and is
serviceable - parts are all on spade connectors. Looks like something
built to 1970s british standards.


So this brings us back to the original statement re external switching.
I am happy to declare, without hesitation "cobblers".

Does anyone wish to add to that, or disagree?

Perhaps some of the manufacturer's fancier models with electronic
controls implement some safety features in software? Those might need
such a warning in the manual, and perhaps the warning has been copied
and pasted into the manuals of other models just in case?

As a minor point, I think the component in your heater is rated at 10000
cycles rather than 10. That's reassuring for me, because the themal
cut-out in the poorly designed no-name oil-filled heater I use operates
frequently.

Its a standard bimetal thermal cutout.
I still stand by my position that expecting to not find cheap is naive. Sorry. And delonghi is not a make I hold in high regard. Marketing image means zip.


NT

wrote in message
...
On Saturday, January 10, 2015 at 6:47:44 PM UTC, Rod Speed wrote:
wrote in message
...
On Saturday, January 10, 2015 at 9:21:25 AM UTC, Tim Watts wrote:
On 10/01/15 09:02, wrote:
On Saturday, January 10, 2015 at 8:27:52 AM UTC, Dennis@home wrote:
On 09/01/2015 23:09, Tim Watts wrote:
On 09/01/15 22:57, wrote:

Engineers often do what's cheapest, a thermistor is cheaper than a
manually resettable bimetal.

Except these are not "cheap" heaters

so what

So you might expect them to not go for something
cheap that might not last as long if its used with a
time switch after its got a fault that the cutout is
protecting against.

On the other hand, they might well decide that
the advantages of automatically resetting rather
than manual resetting is worth it given that the
fault should be rare, like say someone putting
a rug on the heater to dry it and that tripping
the cutout when it gets too hot and its unlikely
that someone would do that and leave it on
a timer for weeks etc.

- and I would expect DeLonghi not top be skimping
on safety devices, especially ones that cause problems
when operating heaters remotely which is waht half
the users can be expected to do...

ah, assumptions

Not assumptions so much as a reasonable expectation.

Its normal practice to go cheap on some parts while
promoting a device as of the highest quality etc.

Turns out that that isn't what DeLonghi has done.

Its business as normal in the world of electricals/electronics.

But clearly not with DeLonghi now that we have a teardown.

Yes many end users have their head in the adverts, but that's the reality.

On 10/01/15 19:34, wrote:
Its a standard bimetal thermal cutout.
I still stand by my position that expecting to not find cheap is naive. Sorry. And delonghi is not a make I hold in high regard. Marketing image means zip.


Could be time to change your view - as I think the construction is
pretty solid - but you have the photos, so feel free to make your own
judgement.

DeLonghi are the best oil rad maker I have come across todate - can you
recommend anyone better?

On 2015-01-10 16:33:16 +0000, Tim Watts said:

On 10/01/15 15:20, Tim Watts wrote:
snip


So this brings us back to the original statement re external switching.
I am happy to declare, without hesitation "cobblers".

Tim,

Thanks for taking the time and trouble to post such an interesting and
comprehensive reply.

I now feel confident about warming my cockles via off-peak electricity...



Regards
Peter

On Fri, 09 Jan 2015 18:23:18 -0000, Tim Watts wrote:

On 09/01/15 17:31, Adrian wrote:

Going on the wording, I'd guess that if the thermal cutout trips, power
is still required to maintain it tripped until a set period of time
expires. If it's switched off, the trip would reset.


I would give that the engineering rating of "a ****ing stupid design" -
criminal even. Manual reset or bimetallic with a very large hysteresis
would be sensible.

But even so, the trip should trip again if it's too hot?

My thoughts exactly. Like if you continuously reset a circuit breaker in the consumer unit, it just trips immediately if the short is still present. It doesn't somehow get "confused" or "annoyed with you" and just let power through and cause a fire.

--
"Get as far away from the nuclear explosion as possible" - Rodney McKay, Stargate Atlantis.

On Fri, 09 Jan 2015 18:20:54 -0000, Tim Watts wrote:

On 09/01/15 17:22, Neddie Seagoon wrote:

Can anyone help me to understand what's going on here, please? Is there
really some material reason why turning the device off and on "at the
mains" is a no-no?


Sounds like utter and complete cock to me.

http://youtu.be/kEkuWCh8UFw

--
Heaven is where the police are British, the chefs Italian, the mechanics
German, the lovers French and it is all organized by the Swiss.

Hell is where the police are German, the chefs British, the mechanics
French, the lovers Swiss and it is all organized by Italians.

On Saturday, January 10, 2015 at 7:49:42 PM UTC, Tim Watts wrote:
On 10/01/15 19:34, wrote:

Its a standard bimetal thermal cutout.
I still stand by my position that expecting to not find cheap is naive. Sorry. And delonghi is not a make I hold in high regard. Marketing image means zip.

Could be time to change your view

So after designing, inspecting and tearing down however many electrical & electronic appliances, I should change my views on how engineers & businesses work simply on the basis of one sample that does not contradict what I said.

- as I think the construction is
pretty solid - but you have the photos, so feel free to make your own
judgement.

DeLonghi are the best oil rad maker I have come across todate - can you
recommend anyone better?

I dont use, design or sell oil rads. I do however have misgivings about the lack of earthing of certain heaters on the market, and the percentage of portable heaters that have safety issues I would probably not welcome in my own home.

FYI domestic appliances are required to remain safe after one fault. For a serious problem to occur, the following would need to happen:
1. thermostat failure
2. coats etc covering much of the heater's area
3. Backup thermal cutout failure

So if you cover the things with clothes, they might have a point. If not there isnt an issue.


NT

On Saturday, January 10, 2015 at 7:40:13 PM UTC, Rod Speed wrote:
wrote in message
...

But clearly not with DeLonghi now that we have a teardown.

on this specific model


NT

On 11/01/15 08:52, wrote:

So after designing, inspecting and tearing down however many
electrical & electronic appliances, I should change my views on how
engineers & businesses work simply on the basis of one sample that
does not contradict what I said.

Ah - if you have experience, then fair comment. You never said...

But do you have any reason to not like DeLonghi - because to me they've
been a decent enough brand - and my teardown verifies that to me.

- as I think the construction is pretty solid - but you have the
photos, so feel free to make your own judgement.

DeLonghi are the best oil rad maker I have come across todate - can
you recommend anyone better?

I dont use, design or sell oil rads. I do however have misgivings
about the lack of earthing of certain heaters on the market, and the
percentage of portable heaters that have safety issues I would
probably not welcome in my own home.

I did notice this one was also earthed. The only fault I've ever found
is 1 of 4 had a bad plug.

FYI domestic appliances are required to remain safe after one fault.
For a serious problem to occur, the following would need to happen:
1. thermostat failure 2. coats etc covering much of the heater's
area 3. Backup thermal cutout failure

So if you cover the things with clothes, they might have a point. If
not there isnt an issue.

On 11/01/15 08:55, wrote:
On Saturday, January 10, 2015 at 7:40:13 PM UTC, Rod Speed wrote:
wrote in message
...

But clearly not with DeLonghi now that we have a teardown.

on this specific model


NT


And how many oil filled electric rads have you seen that use a
thermistor from the DeLonghi range?

And how many from any maker?

I have *never* heard of a thermistor being used as a protective device
controlling a current of around 10A.

wrote in message
...
On Saturday, January 10, 2015 at 7:40:13 PM UTC, Rod Speed wrote:
wrote in message
...

But clearly not with DeLonghi now that we have a teardown.

on this specific model

Bet the others are no worse.

On Sunday, January 11, 2015 at 8:56:36 AM UTC, Tim Watts wrote:
On 11/01/15 08:52, wrote:

So after designing, inspecting and tearing down however many
electrical & electronic appliances, I should change my views on how
engineers & businesses work simply on the basis of one sample that
does not contradict what I said.

Ah - if you have experience, then fair comment. You never said...

But do you have any reason to not like DeLonghi - because to me they've
been a decent enough brand - and my teardown verifies that to me.

there it is:
https://groups.google.com/forum/#!to...-y/r3Il3l0MyGc


NT

On 11/01/15 09:21, Rod Speed wrote:


wrote in message
...
On Saturday, January 10, 2015 at 7:40:13 PM UTC, Rod Speed wrote:
wrote in message
...

But clearly not with DeLonghi now that we have a teardown.

on this specific model

Bet the others are no worse.

FWIW my daughter has the "Dragon" version with a remote control for the
digital timer and thermostat and it has the same type of thermal cutout
so that raises the count to 2.

Although not mentioned in the instructions this model is *not* suitable
for turning off and on "at the mains" - but for a different reason. When
powered off at the mains it "forgets" all its settings and comes back on
with the thermostat set at maximum which I think was about 30C. I think
it also looses all the timer settings but I'm too many miles away to check.

Generally it seems to be built to a similar standard as Tim's. Although
it did fail completely a while ago when the transformer on the control
board PSU dramatically let out all its smoke, but easily and cheaply
fixed by replacing the transformer.

--
Mike Clarke

On 11/01/15 10:00, Mike Clarke wrote:
On 11/01/15 09:21, Rod Speed wrote:


wrote in message
...
On Saturday, January 10, 2015 at 7:40:13 PM UTC, Rod Speed wrote:
wrote in message
...

But clearly not with DeLonghi now that we have a teardown.

on this specific model

Bet the others are no worse.

FWIW my daughter has the "Dragon" version with a remote control for the
digital timer and thermostat and it has the same type of thermal cutout
so that raises the count to 2.

Although not mentioned in the instructions this model is *not* suitable
for turning off and on "at the mains" - but for a different reason. When
powered off at the mains it "forgets" all its settings and comes back on
with the thermostat set at maximum which I think was about 30C. I think
it also looses all the timer settings but I'm too many miles away to check.

Generally it seems to be built to a similar standard as Tim's. Although
it did fail completely a while ago when the transformer on the control
board PSU dramatically let out all its smoke, but easily and cheaply
fixed by replacing the transformer.


I've got a mechanical controlled Dragon - what impressed me is on full
power the draught that emanates from the top - bearing in mind this is
all passive convection.

On 11/01/15 09:59, wrote:
On Sunday, January 11, 2015 at 8:56:36 AM UTC, Tim Watts wrote:
On 11/01/15 08:52, wrote:

So after designing, inspecting and tearing down however many
electrical & electronic appliances, I should change my views on how
engineers & businesses work simply on the basis of one sample that
does not contradict what I said.

Ah - if you have experience, then fair comment. You never said...

But do you have any reason to not like DeLonghi - because to me they've
been a decent enough brand - and my teardown verifies that to me.

there it is:
https://groups.google.com/forum/#!to...-y/r3Il3l0MyGc


NT


Ah - I remember now. Wonder what model that was?

Seems weird as they seemed to have no problem bolting an earth wire to
the case on mine...

wrote
Tim Watts wrote
wrote

So after designing, inspecting and tearing down however many
electrical & electronic appliances, I should change my views on
how engineers & businesses work simply on the basis of one
sample that does not contradict what I said.

Ah - if you have experience, then fair comment. You never said...

But do you have any reason to not like DeLonghi - because to me they've
been a decent enough brand - and my teardown verifies that to me.

there it is:
https://groups.google.com/forum/#!to...-y/r3Il3l0MyGc

Sure, but that is much more likely just a design stupidity
rather than a deliberate attempt to cut costs.

It may have just been an assembly stupidity too, someone
forgot to put the tie that ties the L & N wires together too.

On Sunday, January 11, 2015 at 5:58:12 PM UTC, Rod Speed wrote:
wrote
Tim Watts wrote
wrote

So after designing, inspecting and tearing down however many
electrical & electronic appliances, I should change my views on
how engineers & businesses work simply on the basis of one
sample that does not contradict what I said.

Ah - if you have experience, then fair comment. You never said...

But do you have any reason to not like DeLonghi - because to me they've
been a decent enough brand - and my teardown verifies that to me.

there it is:
https://groups.google.com/forum/#!to...-y/r3Il3l0MyGc

Sure, but that is much more likely just a design stupidity
rather than a deliberate attempt to cut costs.

It may have just been an assembly stupidity too, someone
forgot to put the tie that ties the L & N wires together too.

Whatever you call it, its upto them to police their own goods. I'm just not a fan of large class 0 appliances.


NT

wrote in message
...
On Sunday, January 11, 2015 at 5:58:12 PM UTC, Rod Speed wrote:
wrote
Tim Watts wrote
wrote

So after designing, inspecting and tearing down however many
electrical & electronic appliances, I should change my views on
how engineers & businesses work simply on the basis of one
sample that does not contradict what I said.

Ah - if you have experience, then fair comment. You never said...

But do you have any reason to not like DeLonghi - because to me
they've
been a decent enough brand - and my teardown verifies that to me.

there it is:
https://groups.google.com/forum/#!to...-y/r3Il3l0MyGc

Sure, but that is much more likely just a design stupidity
rather than a deliberate attempt to cut costs.

It may have just been an assembly stupidity too, someone
forgot to put the tie that ties the L & N wires together too.

Whatever you call it, its upto them to police their own goods.

Sure, but that's an entirely different matter to your original
line about being deliberately cheap to make by design.

I'm just not a fan of large class 0 appliances.

It isnt a class 0 appliance.

On Sunday, January 11, 2015 at 9:26:30 PM UTC, Rod Speed wrote:
wrote in message
...
On Sunday, January 11, 2015 at 5:58:12 PM UTC, Rod Speed wrote:
wrote
Tim Watts wrote
wrote

So after designing, inspecting and tearing down however many
electrical & electronic appliances, I should change my views on
how engineers & businesses work simply on the basis of one
sample that does not contradict what I said.

Ah - if you have experience, then fair comment. You never said...

But do you have any reason to not like DeLonghi - because to me
they've
been a decent enough brand - and my teardown verifies that to me.

there it is:
https://groups.google.com/forum/#!to...-y/r3Il3l0MyGc

Sure, but that is much more likely just a design stupidity
rather than a deliberate attempt to cut costs.

It may have just been an assembly stupidity too, someone
forgot to put the tie that ties the L & N wires together too.

Whatever you call it, its upto them to police their own goods.

Sure, but that's an entirely different matter to your original
line about being deliberately cheap to make by design.

no it isnt

I'm just not a fan of large class 0 appliances.

It isnt a class 0 appliance.

it is