Applicable Systems
Octagon 4-Comp
Symptoms
The compressor reports motor overload. The motor current has exceeded the rated full-load value for the protection trip delay.
Possible Causes
- Compressor operating beyond design conditions
- Low supply voltage causing elevated motor current
- Motor winding degradation or partial short
Troubleshooting Steps
- Step 1: Check motor current with a clamp meter against nameplate FLA
Current does not exceed rated full load amps - Step 2: Verify supply voltage at the motor terminals under load
Voltage is within 10 percent of rated value - Step 3: Perform insulation resistance test on motor windings
Insulation resistance exceeds minimum standard
How to Reset
To reset: Clear the overload, allow the motor to cool, then reset the overload relay.
Source: Bitzer Screw Compressor Operating Instructions, Bitzer Kuhlmaschinenbau GmbH
Category: Refrigeration