Protector with inadequate or defective calibration. Check that the starting and running currents are within the limits provided by the compressor manufacturer. Also check the compressor temperature. The absence of overloads or evident overheating shows that the Protective device is insufficient. For different protection systems, proceed as follows:
External thermoamperometric or thermostatic protector: Replace the Protector
Thermoamperometric protector built into the compressor: Replace the compressor.
Frame protector (thermal relay): Check the calibration and if it corresponds to the running current of the compressor, replace the thermal relay.
Thermistor protector: Replace the electronic module with a new one, checking that the current absorbed by the circuit breaker coil that controls the compressor is not higher than that allowed by the electronic module manufacturer. If the dysfunction persists, it means that one of the thermistors in the compressor winding is interrupted (the circuit continuity test is done with an ohmmeter that has a maximum voltage of 1.5 Volt at the ends indicates infinite resistance). An alternative for repairing the compressor is represented by the application, downstream of the circuit breaker, of a properly calibrated thermal relay.
