Bitzer Screw Compressor CSH/CSN Error Code AL2

Bitzer Refrigeration Critical Temperature

Model: Screw Compressor CSH/CSN | Code: AL2

Applicable Systems
Octagon 4-Comp

Symptoms

The compressor reports high discharge temperature. The discharge gas temperature exceeds the maximum allowable limit for safe operation.

Possible Causes

  • Insufficient refrigerant charge causing high superheat
  • Condenser performance degraded raising discharge temperature
  • Compressor internal wear increasing compression work

Troubleshooting Steps

  1. Step 1: Check superheat and subcooling against system design values
    Values are within the specified range
  2. Step 2: Clean condenser and verify fan or water flow operation
    Condenser operates at design capacity
  3. Step 3: Check for refrigerant leaks and recharge to proper charge
    System charge matches the specification

How to Reset

To reset: Lower discharge temperature below the alarm threshold, then reset the controller.

Source: Bitzer Screw Compressor Operating Instructions, Bitzer Kuhlmaschinenbau GmbH

Category: Refrigeration