Replacing a 4 wire motor with a 3 wire motor on Lennox residential outdoor condensers or heat pumps.
THESE INSTRUCTIONS ARE FOR SYSTEMS THAT HAVE A DEDICATED CAPACITOR FOR THE FAN MOTOR (NOT A DUAL CAPACITOR). These instructions are only for use when your motor has three wires... one black wire, one orange wire and one purple wire. In addition to these three wires, you may or may not have a green ground wire on the motor.
**** Wire in this order so you don't get confused ******
The orange wire: This wire must be connected to the same pole on the load side of your contactor that feeds the capacitor (common terminal on dual capacitors). If you do not have a wire that runs from your contactor to your capacitor, you will need to add one (you can cut a wire off of your old motor if you don't have any wire). The orange wire will connect to the load side of the contactor. You will then need to have a wire that runs from the same pole on the contactor that the fan motor orange wire is connected on to the fan motor capacitor. Make sure there is no other wire connected to the fan motor capacitor at this point. At this point, you will have the orange wire on the load side of the contactor and one wire that runs from the same pole of the contactor that the orange wires is connected to the capacitor. Make sure this is the ONLY wire connected to the capacitor.
Black Wire: Connect it to the opposite pole on the contactor from the orange wire.
Purple wire: Connect it to the remaining unused pole on the capacitor.
Your Done! Wasn't that easy?
CozyParts.com, Inc. is an Independent Lennox Dealer providing a national parts distribution resource for Lennox parts since 2002. The Cozy.Support team does not provide a diagnosis for users of this forum. We do, however, try to provide information that will help servicers arrive at their own diagnosis.