wiring a new Tstat for baseboard heater
This is an existing installation that I'm working with.
I want to install a programmable Tstat in place of the existing manual rotary style Tstat.
The baseboard heater is 8 ft long, 240 Volt. I don't know anymore about it.
Coming from the breaker box to the wall junction box there are 4 wires. Grn, Wht, Blk, Red
Then there are 4 more wires continuing on to the heater. The green wires are tied together in the junction box.
It seems to me that I have 2 extra wires in the junction box. (1 to the breaker, 1 to the heater) When I put a meter on the wires coming from the breaker I have black=240V wht=240V and red=110V
I have a 2 pole Tstat (Cadet T4700B) and it seems that I should tie the blk and what 240V lines to it and then put the output to the blk and what lines going to the heater. Is this right?
When I do this the unused wire coming back from the heater to the junction box has 120V on it. Should I terminate this? If so, what's the best way to do this? Or, should it be tied to the 120V line coming from the breaker?
I hope this is clear enough to answer.
Thanks