Protective guard not properly calibrated or defective.
First, check that the starting and running currents are within the limits specified by the compressor manufacturer. Also check the compressor temperature. The absence of overloads or evident overheating demonstrates that a protective protective device is inefficient. For the 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 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 greater than that allowed by the manufacturer of the electronic module. If the dysfunction persists, it means that one of the thermostats in the compressor winding is interrupted (the circuit continuity test done with an ohmmeter that has a maximum voltage of 1.5 Volt at the ends indicates infinite resistance). An alternative to repairing the compressor is represented by the application, downstream of the circuit breaker, of a properly calibrated thermal relay.
