room stat... is it just a switch??

[ashm]

hello and thanks to all that answer,
Could anyone explain why my room thermostat requires three core and earth, i had assumed it was a simple switch :- live, switched live and earth. had read something, somewhere about an anticipator- is this the third wire? P.S its a honeywell stat

thanks

 

[sanj.varah]

the simple ones just run a live and a switched live.

the more sophisticated ones which have hysterisis have a dedicated live. Hysterisis prevents the switch cycling on and off very fast when you get near the set point.

 

[ashm]

that makes sense, thanks for the reply!

 

[breezer]

older ones had a resitor , so required a neutral

 

[gas4you]

older ones had a resitor , so required a neutral

Known as an anticipator I believe.

 

[Softus]

the simple ones just run a live and a switched live.

the more sophisticated ones which have hysterisis have a dedicated live. Hysterisis prevents the switch cycling on and off very fast when you get near the set point.

To be pedantic, for a change, it's the simple ones that need three wires, and the sophisticated ones that overcome the need for the third wire.

 

[Lectrician]

The resistor produces a little heat - it is known as an accelorator resistor, and it is to cut the hysterisis when near to temp.

 

[Softus]

Sometimes it's known as an accelerator.

 

[Lectrician]

Whats an e between friends?

 

[tim west]

This is an Accelerator:

This is an Accelerator pedal (one on the right):

And this is an Anticipator:

 

[Lectrician]

I have always known it as accelerator resistor - In fact, most manufacturers also call it this

 

[ricicle]

Anticipator

 

[Trazor]

To be pedantic, for a change

 

[Lectrician]

To be pedantic, for a change

Pedentic

 

[tim west]

pandantic: