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View Full Version : Wire exhaust fan to thermostat


Booman2
Jan 26, 2007, 04:46 PM
I'm trying to wire an exhaust fan to a thermostat in a green house so when temp reaches 80 degrees fan will come on and stay on until thermostat is satisfied. The only power source is an outlet in green hs. Going to use an old power tool cord cut off an old power tool. Plug it into the outlet and strip the other end (2wires) and connect them to a transformer to reduce voltage to 24v. This is where I get stumped. I have 24v transformer ,24v relay,thermostat and fan but not enough electrical sense to bring them together for the desired operation.Going to run all of this through GFI just in case. Can someone please help so granny don't lose all her vegies?:confused:

labman
Jan 26, 2007, 05:29 PM
Does the thermostat have a terminal marked Y and another marked R or RC? Starting with cord. Wire the white wire to one lead of the fan and one lead of the transformer. Make it the white ones if there are any. Wire the black wire to the other lead of the transformer and to the terminal of the relay marked line. Wire the other lead of the fan to the terminal marked load. All those connections should be made in a metal electrical box with the green wire from the cord connected to it.

Start with one of the other wires from the transformer, often red or yellow. Connect it to the R or RC terminal of the thermostat. Run another wire from the Y terminal to one of the coil terminals of the relay. Finally run a wire from the other coil terminal to the last lead of the transformer. Those can be light duty wire, bell wire or thermostat wire.

Make sure the cord you use is heavy enough to power the fan.