Good morning. My friend have a big electric heathing system working on 600 volt 3 phase.
He get mercury thermostat (with two litle botle of mercury) working on 24 volt. He get 3 wire connected on.(one black one red and one white ). My question is ,if I can connect this
Thing on a new thermostat an how conncect that wire.
Thank you very mutch

First you must determine which wire is which, look on the heater where these wires connect, should be a letter designation such as red wire to "R", connect these wires to the same terminal on the thermostat. You will be connecting the "R", "W1", and "W2" for two stage heat. Good luck, Mike