Kaeser SIGMA CONTROL 2 Fault Codes
Kaeser compressors with SIGMA CONTROL 2 (second generation) use text-based alarm messages displayed on the controller panel. The SIGMA CONTROL 2 provides more detail and connectivity than the original Sigma Control, including Ethernet integration and remote monitoring via SIGMA NETWORK.
SIGMA CONTROL 2 Fault Reference
| Alarm Message | Category | Common Cause | Action |
|---|---|---|---|
| Final compression temp ΓÇö Warning | Warning | Approaching high temp limit | Clean coolers, check oil |
| Final compression temp ΓÇö Shutdown | Shutdown | Excessive temperature | Clean coolers, check oil, check ambient |
| Motor protection ΓÇö Shutdown | Shutdown | Motor overload | Check motor amps and load |
| Emergency stop ΓÇö Active | Shutdown | E-stop circuit open | Check all E-stop switches |
| Pressure sensor ΓÇö Fault | Warning | Failed pressure transducer | Check sensor wiring and signal |
| Temperature sensor ΓÇö Fault | Warning | Failed temperature sensor | Check sensor resistance |
| Dryer ΓÇö Fault | Warning | Integrated dryer alarm | Check refrigerant dryer operation |
| Service ΓÇö Required | Maintenance | Service interval reached | Perform scheduled service |
| Fan motor ΓÇö Fault | Shutdown | Cooling fan motor fault | Check fan motor amps and contactor |
| Condensate drain ΓÇö Fault | Warning | Drain solenoid not operating | Check drain solenoid and timer |
| Oil filter ΓÇö Service | Maintenance | Oil filter replacement due | Replace oil filter element |
| Differential pressure ΓÇö High | Warning | Separator element clogged | Replace separator element |
| Communication ΓÇö Fault | Warning | Network communication loss | Check Ethernet and network config |
| Phase ΓÇö Fault | Shutdown | Phase loss or reversal | Check input power quality |
Most Common SIGMA CONTROL 2 Faults
Final Compression Temp ΓÇö Shutdown
Kaeser’s shutdown threshold is typically 110┬░C (230┬░F). Warning precedes shutdown by approximately 5┬░C. Root cause is almost always a dirty cooler. Kaeser SIGMA CONTROL 2 logs the temperature trend ΓÇö review to see if temp is climbing progressively or suddenly.
Dryer Fault
On packages with integrated refrigerated dryer, the SIGMA CONTROL 2 monitors dryer operation. Dryer fault triggers if the dryer controller generates an alarm. Check the dryer controller (separate display inside the package) for a specific fault. Common: dryer refrigerant pressure alarm, condenser fan fault, or high pressure dewpoint.
Service Required
SIGMA CONTROL 2 tracks service intervals by operating hours. Service due alerts appear in advance of the actual service interval (configurable, typically 100 hours before). Perform Kaeser-specified maintenance and reset the service counter in the SIGMA CONTROL 2 menu (requires service password).
Communication Fault
SIGMA CONTROL 2 supports Modbus, PROFIBUS, PROFINET, and Ethernet. A communication fault means the controller cannot communicate with the BMS, master controller, or SIGMA NETWORK. Check network cable connections and verify IP address configuration.
Parts Commonly Needed
| Part | Notes |
|---|---|
| Oil separator element | Amazon | Kaeser-specific ΓÇö match model |
| Oil filter element | Amazon | Match package model |
| Pressure transducer | Amazon | Check signal output (typically 4ΓÇô20 mA) |
| Temperature sensor | Amazon | NTC thermistor ΓÇö check resistance |
| Condensate drain solenoid | Amazon | Match voltage and orifice size |
| Fan motor contactor | Amazon | Check contact condition |
Pro tip: Kaeser SIGMA CONTROL 2 can be connected to SIGMA NETWORK for remote monitoring. Kaeser service centers can remotely access fault logs and performance data. Register the compressor on SIGMA NETWORK to enable predictive maintenance alerts.