trader_4 wrote
Rod Speed wrote
Davej wrote
Rod Speed wrote
Davej wrote

Can anyone explain the internal circuit of a 3-pin
refrigerator thermostat such as a WDF-18 ? Thanks.

https://www.amazon.com/s/ref=nb_sb_n...tor+thermostat

One terminal is the common. That is connected to one
or other of the other two terminals depending on
whether the temperature is above or below the set point.

Oh, so what would a refrigerator need to apply
power to when it shuts off the compressor?

It doesnt, its just the way thermostats are usually done.

Not likely, I bet there is a wire connected to all three
terminals. It may be part of a design so that the defrost
heater is only powered when the compressor is off.

Makes a lot more sense to do that in the controller, not the thermostat.