How do you reverse the direction of a split-phase motor?

How do you reverse the direction of a split-phase motor?

• A. Reverse the polarity to the start winding
• B. Reverse the polarity to the run winding
• C. Disconnect the power supply
• D. Swap windings with a capacitor

Answer: (A)

Split-phase motors create their rotating magnetic field from the main run winding and a shifted-start winding. The start winding, with the capacitor, provides a phase-shifted current that leads or lags the run winding, producing a rotating field in a specific direction. Reversing the polarity of the start winding changes the relative phase between the two windings, which flips the direction of the rotating magnetic field and thus reverses the motor’s rotation. Disconnecting power only stops the motor. Swapping windings with a capacitor isn’t the standard method to reverse direction and wouldn’t reliably achieve reversal. So reversing the start winding polarity is the correct way to change direction.

Split-phase motors create their rotating magnetic field from the main run winding and a shifted-start winding. The start winding, with the capacitor, provides a phase-shifted current that leads or lags the run winding, producing a rotating field in a specific direction. Reversing the polarity of the start winding changes the relative phase between the two windings, which flips the direction of the rotating magnetic field and thus reverses the motor’s rotation. Disconnecting power only stops the motor. Swapping windings with a capacitor isn’t the standard method to reverse direction and wouldn’t reliably achieve reversal. So reversing the start winding polarity is the correct way to change direction.