Electrician to test sockets? Scam or not??

[Stoday]

Al the biasing resistor does is adds a bit of ambient heat so that the thermostat is immune to cold drafts from clicking it on and off constantly. Now I have not delved too deep into this so perhaps someone in the know could confirm this is the case

No, it's not. In fact, quite the contrary, the accelerator resistor speeds up the thermostat's response rather than slowing it down.

Current flows through the resistor when the thermostat calls for heat, so it gets warmed by both the room air and the heat from the resistor. It reaches the set temperature more rapidly than if the 'stat relied on the room air temperature alone. This corrects for the room heater warming up the room air more quickly than the thermostat's bimetal sensor can respond.

Electronic thermostats have a sensing element that has a much lower thermal mass and thus do not require accelerator heaters.

 

[bernardgreen]

The "accelerator" compensates for fact that there is a difference in the temperatures at which the switch in the thermostat operates. This is the hysterisis of the switch and is necessary to ensure a snap action of the contacts

If a mechanical thermostat without the accelerator connected is set to turn on at 16 degrees it will not turn OFF until the temperature of the bi-metal strip is a few degrees above 16. The resistance acts as a heater to raise the air temperature around the bi-metal strip the a few degrees above the temperature of the air around the thermostat to compensate for the hysterisis. Electronic thermostats have a different way to ensure snap action which has a hysterisis of less than a tenth of a degree

 

[SUNRAY]

Does it look like the cupboard socket is on a 32A?

Wonder if cable is rated accordingly?

If its 2.5mm, then yes it is correctly rated on a 32A MCB. If fact strictly speaking 1.5mm also complies.

 

[SUNRAY]

Very interesting post which just backs up my decision a few years ago to always insist and charge for a PIR in advance of a board change (in fact I don't give my customers the option - some other fool can take the work ta very much). I can't believe I used to just go for it - and often be there til late trying to fix a problem...

Something to be said for getting old - you get a bit more sensible!

SB

Good point.

Well presented.

 

[holmslaw]

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[SUNRAY]

Does it look like the cupboard socket is on a 32A?

Wonder if cable is rated accordingly?

If its 2.5mm, then yes it is correctly rated on a 32A MCB. If fact strictly speaking 1.5mm also complies.

Still talking nonsense. 1.5 cable is not suitable for 32A circuit protection and 2.5 can only be used with 32A protection under specific conditions.

When its this short and protected down stream with a single 13A fuse...

But no I wouldnt do it.

 

[holmslaw]

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[ban-all-sheds]

SUNRAY - please leave it - don't feed the troll.