Kaeser K005: Kaeser ASD/BS Series Error Code K005

Symptoms

Refrigerated dryer dew point temperature is higher than the setpoint (e.g., >3C when set to +3C). The integrated dryer control reports a dew point alarm to the Sigma Control 2.

Possible Causes

Refrigerant charge low due to a micro-leak in the dryer evaporator or piping
Condenser fins blocked with dust, reducing heat rejection and refrigerant subcooling
Hot gas bypass valve stuck open, sending warm refrigerant gas into the evaporator
Ambient temperature around the dryer exceeds 45C, exceeding the dryer rating

Troubleshooting Steps

Step 1: Check the dryer sight glass for bubbles and the suction line temperature
If bubbles are present and suction is warm, recover refrigerant, leak-test with tracer gas, and recharge to nameplate weight
Step 2: Clean the dryer condenser fins with foaming cleaner and a soft brush
Verify airflow through the condenser with a tissue paper test - the paper should cling firmly to the grille
Step 3: Check the hot gas bypass valve operation by monitoring evaporator pressure during load changes
Replace the valve if it fails to throttle correctly; the valve should modulate to maintain 0C evaporating temperature
Step 4: Measure the room temperature at the dryer intake - it must not exceed 45C for standard units
Improve room ventilation or relocate the dryer to a cooler area if ambient is excessive

How to Reset

Reset: After repairing the dryer, press the Dryer Reset button on the Sigma Control 2. The dew point alarm clears when the measured dew point stays below the setpoint for 10 minutes.

Common Replacement Parts

6.2010.0: Refrigerant charge, R-134a, 1.2 kg (For integrated TD 31 dryer, charged by weight)
6.2011.0: Hot gas bypass valve, TD 31 (Sporlan ADRHE-3, 3/8 ODF)
6.2012.0: Condenser fan motor, TD 31 (0.12 kW, 220V single-phase, 1300 RPM)

Frequently Asked Questions

Q: What dew point should my dryer achieve?
A properly sized and maintained refrigerated dryer should achieve a pressure dew point of +3C to +5C at rated flow. Below +2C risks freezing the condensate drain.
Q: Can I run the compressor if the dryer dew point is high?
Yes, but downstream equipment may experience moisture-related failures. Monitor the downstream filter drains for excessive water and plan dryer repair promptly.

Kaeser ASD/BS Series Error Code K005