To reverse the rotation of a split-phase motor, which action is used?

• A. Reversing the two connections to the starting relay
• B. Reversing the connections to the starting capacitor
• C. Interchanging the starting winding leads
• D. Reversing the plug in the electrical supply outlet

Answer: (C)

Rotation direction in a split-phase motor is determined by the phase relationship between the run winding and the starting winding. The starting winding (often with a capacitor) creates a phase-shifted current that produces a rotating magnetic field. If you want the motor to spin the other way, you must flip that phase relationship so the rotating field spins in the opposite direction. The most direct way to do this is by interchanging the leads of the starting winding (and, if a capacitor is used, the associated capacitor leads). Swapping those leads changes which winding current leads or lags, reversing the direction of the rotating field. Reversing the plug in the outlet or altering the starting relay alone doesn’t reliably reverse rotation, since they don’t change the relative phase between the two windings.