Irinox A57

What does Irinox A57 mean?

The control board has detected an abnormally low temperature at condenser 2, as reported by the DT sensor on that circuit. This manual-reset alarm applies to the larger M/ML and L/LL MultiFresh Next models which are equipped with multiple condenser circuits. The controller has determined that the measured condensing temperature on circuit 2 has fallen below the acceptable minimum, halting the cycle until the fault is investigated and manually cleared.

Symptoms

• A57 alarm code displayed on the control panel, unit in blocked state
• Condenser 2 DT sensor reading is lower than expected for current operating conditions
• Cycle interrupted; unit will not restart without a manual reset
• Possible imbalance between condenser circuits if condenser 1 reads normal while condenser 2 reads low
• Alarm event logged in the controller history with timestamp

Common causes

• Faulty or out-of-calibration DT sensor on condenser 2 generating a false low reading
• Open circuit or damaged wiring in the condenser 2 DT sensor cable
• Refrigerant charge imbalance or loss on the condenser 2 circuit
• Overcooling of condenser 2 due to excessively low ambient or water-supply temperature
• Incorrect calibration offset for condenser 2 DT sensor stored in controller parameters
• Water flow rate too high on water-cooled condenser 2 causing excessive subcooling

Diagnostic steps

1. 01

   Read live condenser 2 DT sensor value

   Navigate to the live sensor display in the controller service menu and record the condenser 2 DT reading. Compare it against condenser 1 and ambient conditions to determine whether the reading is anomalous.

2. 02

   Inspect sensor wiring for condenser 2

   Check the DT sensor wiring harness for condenser 2 from the sensor head to the control board terminal. Look for broken conductors, chafed insulation, or loose terminals that could create an open or high-resistance circuit.

3. 03

   Measure DT sensor resistance

   Disconnect the condenser 2 DT sensor and measure its resistance at known ambient temperature. Cross-reference the result with the NTC table in the Irinox service manual; replace the sensor if readings are out of range.

4. 04

   Assess installation and water conditions

   For air-cooled units, verify that ambient temperature is within spec. For water-cooled units, check the water inlet temperature and flow rate to condenser 2; excessively cold or high-flow water can legitimately cause low condensing temperature on this circuit.

5. 05

   Verify controller calibration offset

   In the controller service parameters, confirm the calibration offset for the condenser 2 DT sensor is set correctly. Correct any erroneous value that is artificially depressing the reported temperature.

6. 06

   Reset and run supervised test cycle

   After correcting the identified fault, perform the manual reset. Observe condenser 2 DT readings throughout a full test cycle to confirm they remain within the normal operating band.

When to call a professional

If low condenser 2 temperature persists after sensor, wiring, and calibration checks, escalate to a licensed Irinox-certified refrigeration technician to evaluate refrigerant charge and circuit pressures on condenser 2. Water-cooled installations with suspected control valve or flow regulation issues should also be referred to a qualified technician.