A Motor Control Circuit ( Part 1 )

A motor control circuit (Part 2), (Part3)

Troubleshooting a motor control circuit should always be done beginning with the most obvious components. By checking the most obvious components first, the trouble is often quickly found and may be easily rectified. A basic procedure to follow when troubleshooting a motor control circuit is:

1. Check supply voltage.
2. Check all terminal connections.
3. Check fuses.
4. Check magnetic starter.
5. Check push buttons.
6. Check coil.

Checking Supply Voltage

Supply voltage is checked by using a voltmeter. See figure below. Measure the phase-to-phase voltage from supply side, L1 to L2, L1 to L3, and L2 to L3. Read the phase-to-phase voltage. For example, the phase-to-phase voltage may be 48 volts or 240 volts.