Applicable Systems
Octagon 4-Comp
Symptoms
The compressor reports low suction pressure. The suction pressure has dropped below the minimum safe operating threshold.
Possible Causes
- Low refrigerant charge from system leak
- Evaporator airflow restricted or iced
- Expansion valve malfunction or blockage
Troubleshooting Steps
- Step 1: Check suction pressure against the refrigerant saturation chart
Pressure corresponds to the correct evaporation temperature - Step 2: Inspect evaporator for ice or restricted airflow
Evaporator is clean and airflow is normal - Step 3: Test expansion valve operation and superheat setting
Valve maintains correct superheat
How to Reset
To reset: Raise suction pressure above the threshold, then acknowledge the alarm.
Source: Bitzer Screw Compressor Operating Instructions, Bitzer Kuhlmaschinenbau GmbH
Category: Refrigeration