U.S. Seal Start Capacitor 378-455 MFD, 110V, BC-378

BC-378 is a replacement start capacitor rated 378 to 455 MFD, for 110V and 125V service, supplied by U.S. Seal.

What a start capacitor does

A single phase motor cannot start itself on the running winding alone. The start capacitor provides the phase shift that produces starting torque, holds it until the motor is near speed, and then a switch takes it out of circuit. It works hard for a couple of seconds every time the pump starts, which is why it is one of the first things to fail on an aging motor.

Matching the part

Go by the numbers on the capacitor you are removing, not by the motor. The MFD range and the voltage rating are what have to match. Compare them against 378 to 455 MFD and 110V or 125V before ordering.

Handle it discharged

Capacitors store energy after the power is off. Discharge the old one safely before you disconnect it, and keep your hands off both terminals at once.