Applicable Systems
GA Series Compressed Air System
Symptoms
The compressor reports an unload valve fault. The unloading valve is not operating correctly.
Possible Causes
- Unload valve solenoid coil failure
- Valve spool stuck from contamination
- Unload valve control circuit fault
Troubleshooting Steps
- Step 1: Test the unload valve solenoid coil
Coil shows correct resistance - Step 2: Inspect and clean the valve spool
Spool moves freely between positions - Step 3: Verify the control circuit operation
Circuit delivers signal to the valve
How to Reset
To reset: Repair the unload valve, then clear the alarm.
Source: Atlas Copco Compressor Manual, Atlas Copco AB
Category: Hydraulic & Pneumatic