9.2.0 - Symptom 2: Compressor Hums But Will Not Start

9.2.1

Contactor

1.

Check contacts and contactor operation.

9.2.2.

Low voltage

2.

Check voltage at main and at the unit. If voltage is okay at the main but voltage is low at the unit increase the wire size. If low at main, consult Power Co. Voltage must be +\- 10% nameplate rating.

9.2.3.

No power on one phase of a three phase unit.

3.

Check fuses in control panel and main disconnect. Also check wiring

4.

Check main plant fuse and wiring

5.

If problem is with the main power supply coming into the plant, call local power company.

9.2.4.

Loose terminals

6.

Tighten terminals with "POWER OFF."

9.0 | 9.1 | 9.2 | 9.3 | 9.36 | 9.3.11 | 9.4 | 9.5 | 9.6 | 9.7 | 9.8