Applicable Systems
Carrier Transicold Refrigeration Unit
Symptoms
The Carrier Transicold unit displays alarm CR010, indicating air in the system. Non-condensable gases are causing high head pressure and reduced cooling capacity.
Possible Causes
- System was not properly evacuated before charging, leaving trapped air in the system
- System has been operated in a vacuum, pulling air in through a low-side leak
- Compressor motor burnout has released non-condensable gases from oil decomposition
Troubleshooting Steps
- Step 1: Perform a purge test by comparing the condenser pressure to the refrigerant saturation pressure at the condenser outlet temperature
Condenser pressure matches the saturation pressure, confirming no non-condensable gases - Step 2: Check the discharge temperature and the approach temperature across the condenser
Approach temperature is 2-5C, confirming the condenser is operating efficiently without air - Step 3: Verify the system was properly evacuated and the standing vacuum test holds at 500 microns for 30 minutes
Vacuum holds below 500 microns for 30 minutes, confirming the system is free of non-condensable gases
How to Reset
To reset: 1) Recover the refrigerant. 2) Replace the filter drier. 3) Evacuate to below 500 microns and hold for 30 minutes. 4) Recharge to the nameplate weight. 5) Press RESET and verify head pressure.
Source: Carrier Transicold Refrigeration Unit Manual, Carrier Corporation
Category: Refrigeration