When is it advisable to replace a capacitor in a single-phase motor?

Replacing a capacitor in a single-phase motor is advisable when the capacitor is visibly damaged or showing signs of failure. Capacitors are critical components in single-phase motors, particularly in starting applications, where they help provide the necessary phase shift for starting and running the motor efficiently.

If a capacitor is damaged—such as through bulging, leaking, or discoloration—it may fail to perform its function effectively, potentially leading to motor malfunctions like poor starting performance, reduced torque, or overheating. Such failures can also cause stress on the motor itself and may ultimately lead to complete motor failure, making timely replacement essential to ensure continued operation and to prevent further damage.

While factors like excessive vibration or a smoothly running motor might indicate issues, they do not provide direct evidence of capacitor health. Similarly, stable voltage supply indicates good electrical conditions but does not guarantee that the capacitor is functioning correctly. Therefore, visible damage is a clear and reliable indicator for determining when a capacitor needs to be replaced.