CompAir Compressor Fault Codes - Quick Reference
CompAir (Gardner Denver brand) rotary screw compressors use the Delcos XL and Delcos Pro controllers on L, D, and B series machines. Alarms fall into warnings (continue running) and shutdowns (compressor stops).
| Fault | Meaning | Quick Fix |
|---|---|---|
| High Discharge Temp | Air/oil temperature exceeded | Check cooler, oil level, fan |
| Low Oil Level | Oil level sensor triggered | Add oil, check for leaks |
| Motor Overload | Motor current too high | Check phases, load, voltage |
| High Pressure | System pressure exceeded set point | Check pressure relief, regulator |
| E-Stop | Emergency stop circuit open | Reset E-stop, inspect wiring |
| Service Due | Maintenance interval reached | Perform PM, reset counter |
| Oil Separator DP High | Separator restricted | Replace separator element |
| Sensor Fault | Sensor signal out of range | Check sensor and wiring |
| Phase Fault | Phase loss or imbalance | Check supply voltage |
| Blowdown Valve | Valve not operating correctly | Inspect valve actuator |
Most Common Faults
High Discharge Temperature
Clean the cooler bundle and verify fan operation first. CompAir oil coolers are often cooled by a fan driven by the main motor belt or a separate motor - check that the fan runs at full speed. Also check oil type and level; synthetic oil is strongly preferred.
Oil Separator DP High
Separator element typically needs replacement every 2,000–6,000 hours depending on operating conditions. Running dusty environments accelerates clogging. A blocked separator increases energy consumption and causes oil carryover into the air system.
Phase Fault
CompAir machines are sensitive to supply voltage quality. Missing phase, voltage imbalance above 3%, or frequent dips trigger this fault. Verify at the incoming terminal block under load, not just at the disconnect.
Motor Overload
Check current draw on all three phases with a clamp meter. Unbalanced loading, incorrect motor rotation on initial setup, or a sticking inlet valve can all cause nuisance overloads.
Parts Often Needed
| Part | Notes |
|---|---|
| Oil separator element | Amazon | Main PM part |
| Air filter element | Amazon | Replace per service schedule |
| Oil filter cartridge | Amazon | Replace with separator |
| Temperature sensors (NTC) | Amazon | Common fault after heat cycles |
| Inlet valve repair kit | Amazon | Sticking causes overloads |
When to Call a Pro
If the compressor shuts down on high temperature after cooler cleaning and oil service, suspect airend discharge valve or screw wear. CompAir airend rebuilds require factory tooling and specifications.