Cooling fan
Common VFD, drive, UPS, and cabinet overheating failure point.
Atlas Copco Compressor Fault Codes — Quick Reference
Atlas Copco rotary screw compressors with Elektronikon controllers display warnings, service reminders, and shutdown alarms tied to temperature, pressure, motor overload, and sensor faults. The exact code list varies by generation, but these are the alarm families technicians see most often.
| Alarm | Meaning | Quick Fix |
|---|---|---|
| High Element Outlet Temp | Compressor running too hot | Check coolers and oil level |
| High Dew Point | Dryer not performing | Check refrigerant dryer and condensers |
| Main Motor Overload | Motor current too high | Check load and motor amps |
| Sensor Fault | Temp or pressure sensor signal bad | Check sensor wiring |
| Emergency Stop | E-stop circuit open | Reset E-stop and inspect circuit |
| Service Due | Preventive maintenance interval reached | Perform service and reset counter |
| Separator Differential High | Oil separator restricted | Replace separator |
| Low Oil Pressure | Lubrication fault | Check oil level and filter |
Most Common Faults
High Element Outlet Temperature
This is one of the most common shutdown causes on rotary screw compressors. Dirty coolers, low oil level, failed cooling fan, or high ambient temperature all drive discharge temperature up. Start by blowing out the oil cooler and aftercooler with dry compressed air in the opposite direction of normal airflow.
Separator Differential High
A restricted oil separator creates excessive pressure drop and poor oil carryover control. Replace the separator element if the differential stays high after service. Running too long with a plugged separator increases energy use and oil carryover.
Motor Overload
Check line voltage, current balance, and actual compressed air demand. A compressor cycling between loaded and unloaded modes too aggressively may need control tuning or a storage tank review, not just a motor reset.
Parts Often Needed
| Part | Notes |
|---|---|
| Air/oil separator | Major service item |
| Oil filter | Replace with separator service |
| Temperature sensor | Common after vibration and heat cycling |
| Cooling fan / contactor | Common on overheats |
Need Replacement Parts?
Before ordering, match the commercial equipment part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
When to Call a Pro
If the compressor repeatedly trips on temperature or motor overload after routine service, involve an Atlas Copco technician. Screw compressor control problems and internal airend wear are not guess-and-check repairs.