Motor Trouble-Shooting (10)

Start capacitors continuously fail.

Like Causes:
1. The motor is not coming up to speed quickly enough.
2. The motor is being cycled too frequently.
3. Voltage to motor is too low.
4. Starting switch may be defective, preventing the motor from coming out of start winding.

What To Do:
1. Motor may not be sized properly. Verify how long the motor takes to come up to speed. Most single phase capacitor start motors should come up to speed within three seconds. Otherwise the
capacitors may fail.
2. Verify duty cycle. Capacitor manufacturers recommend no more than 20, three-second starts per hour. Install capacitor with higher voltage rating, or add bleed resistor to the capacitor.
3. Verify that voltage to the motor is within 10% of the nameplate value. If the motor is rated 208-230V, the deviation must be calculated from 230V.
4. Replace switch.


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