Applicable Systems
Carrier Transicold Refrigeration Unit
Symptoms
The Carrier Transicold unit displays alarm CR009, indicating refrigerant leak detected. The system refrigerant charge has dropped below the minimum operating level, risking compressor damage from low suction pressure.
Possible Causes
- Refrigerant leak at a flared or brazed fitting that has loosened from vibration
- Evaporator or condenser coil has developed a pinhole leak from internal corrosion
- Schrader valve on the service port is leaking through a damaged core or cap seal
Troubleshooting Steps
- Step 1: Perform an electronic leak detector sweep of all joints, fittings, and coils
No leak is detected at any joint or fitting after a thorough sweep at operating pressure - Step 2: Check the suction and discharge pressures against the expected values for the current conditions
Pressures are within the expected range and the system holds a stable charge - Step 3: Verify the system charge by weighing the refrigerant or measuring subcooling
Charge weight matches the nameplate value and subcooling is within 3-5C of the design value
How to Reset
To reset: 1) Locate and repair the leak. 2) Replace the filter drier. 3) Evacuate and recharge to the nameplate weight. 4) Press RESET and verify pressures are stable for 1 hour.
Source: Carrier Transicold Refrigeration Unit Manual, Carrier Corporation
Category: Refrigeration