Motor Start, Motor Run Capacitors (AC) (1831)

A motor start capacitor provides a temporary power boost to help single-phase electric motors start by creating a phase shift in the windings and is disconnected once the motor reaches operating speed. A run capacitor, on the other hand, stays in the circuit continuously, improving efficiency, torque, and power factor while the motor runs. If a start capacitor fails, the motor may hum, struggle to start, or fail entirely, whereas a faulty run capacitor can cause overheating, reduced efficiency, or motor stalling under load.