Room temperature sensor

[jim the box]

I was thinking of adding a thermocouple to a lighting switch faceplate to save on wiring, the thermocouple would control the temperature back at the control cupboard.

Any reasons why it couldn't be done?

[martyn.wendon]

Any reasons why it couldn't be done?

Probably not, but if you include a little bit more information then we might be able to advise further

[jim the box]

Probably not, but if you include a little bit more information then we might be able to advise further

I am running CAT6 cables to my light switches (low voltage) and have a couple of cores spare. I thought that I could put a PT100 thermocouple on these and mount the thermocouple poking out of the bottom of the plastic light switch plate.

I am not sure if it is in the best place (height is OK but I'm not sure about near the door) for the thermocouple to be effective.

[martyn.wendon]

I don't see a problem with it technically - not used the PT100 myself, but presume that it will be ok operating over that distance cable-wise.

As for the location, I know some people that have done similar, but it's not a location I'd choose myself - typically the door will be away from the main areas where people will be and may also be in a draught-prone area. In my own heating system (currently based on ELV / FS20 wire-less devices) I tend to site the thermostats where people will be spending most time e.g. in the living room this is near the sofa, dining room it's near the dining room table, bedrooms close to the bed etc.

[jim the box]

Thanks martyn, Pt100 uses a compensating wire to negate the extra resistance for the distance.