I need to install a White Rodgers transformer thermal control relay combination on my gas furnace but I am not sure of the wiring connections.
This is going to be a tough one to explain, but from the schematic I found, this is a transformer/controller all in 1. So we are using this 1 module for 2 purposes. The R terminal should connect to the wire that's connected to R at the thermostat. And the C terminal should connect to the C wire coming from the C terminal at your t-stat(if used), as well as your common that returns power from your contactor at the o.d. unit. You'll have 2 wires going to the o.d. unit, 1 connects to Y and 1 connects to C to the 8a501 box. The G and W should also be connected to the wires that connect to G and W at the t-stat. That is your low voltage side. Now, this line voltage side is more difficult. You'll need to know what wires are your fan speed taps on your blower motor. And also, does your unit close the N/O(normally open) contacts for heat or cool? Normally it closes for cooling, so your high speed wire would connect to the n/o wire, and your line voltage supply would connect to the bulk/yellow. And then your medium or low wire from your blower would connect to the N/C wire. The schematic is there on the side of the module. This may be beyond your experience and may cause motor winding failure with in seconds of operation. Also, ensure with a volt meter that all power is disconnected! And all run capacitors are discharged! I've not wired 1 of these modules but from the schematic, seems simple, AS LONG AS YOU KNOW WHAT THE MOTOR SPEED TAPS ARE. Hope this helps, and if you're unsure, call a professional. The labor should be less than the cost of a damaged motor.
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