3-Wire vs 4-Wire Condenser Fan Motor Wiring

The main difference between the two wiring configurations lies in the utilization of the brown-and-white wire. The 4-wire configuration uses the brown wire as the capacitor lead and the brown-and-white wire as the capacitor common. The white and brown-and-white wires are actually the same; the brown-and-white wire is an automatic jumper with the actual connection inside the motor.

In many cases, you’re also replacing the factory or OEM capacitor with a universal dual capacitor. In those cases, you can use the 3-wire configuration by cutting the brown-and-white wire back at the motor and putting a wire nut on it or running it into the cabinet and capping it there. The three-wire configuration requires you to run a jumper from the white wire to the other side of the capacitor.