Applicable Systems
Carrier Transicold Refrigeration Unit
Symptoms
The Carrier Transicold unit displays alarm CR012, indicating temperature sensor drift. A discharge or space temperature sensor is reading outside its calibrated range, causing inaccurate temperature control.
Possible Causes
- Sensor element has drifted from calibration due to age and thermal cycling
- Sensor wiring has developed high resistance from a loose connection or corrosion
- Controller input channel has drifted and requires recalibration against a reference source
Troubleshooting Steps
- Step 1: Compare the sensor reading to a calibrated reference thermometer at the same location
Sensor reading matches the reference within 1C, confirming the sensor is accurate - Step 2: Check the sensor wiring resistance and the connection tightness at the sensor and controller terminals
Wiring resistance is negligible and all connections are tight with no corrosion - Step 3: Perform a controller input channel calibration using the calibration procedure in the manual
Controller input reads correctly after calibration, matching the reference signal
How to Reset
To reset: 1) Replace the drifted sensor with a new calibrated unit. 2) Repair wiring and connections. 3) Recalibrate the controller input channel. 4) Press RESET and verify temperature control is accurate.
Source: Carrier Transicold Refrigeration Unit Manual, Carrier Corporation
Category: Refrigeration