In this article, we will explain how to diagnose low refrigerant levels in a refrigeration or air conditioning system without using gauges, relying instead on indirect measurements.
1. Measuring Electrical Consumption with a Clamp Meter
A clamp meter is a crucial tool for this diagnosis, as it allows you to measure a system’s electrical consumption without direct intervention.
- Symptom: If the system has low refrigerant levels, the recorded electrical consumption will be lower than the normal value.
- Reference Value: This normal value, known as the RLA (Rated Load Amperage) on compressors, can be found on the system’s technical plate.
- Example: If the clamp meter shows a consumption below the RLA, this could indicate low refrigerant levels.
- Important Note: A drop in electrical consumption alone does not confirm low refrigerant. Other symptoms must also be verified.
2. Temperature Difference in the Evaporator
Measure the temperature at the evaporator’s inlet and outlet.
- Symptom: If the temperature difference between the inlet and outlet exceeds 10°C to 15°C, it may indicate low refrigerant levels.
- Normal Condition: Under normal circumstances, this difference should not exceed 5°C.
3. Temperature Measurement at the Compressor Discharge
Measure the temperature at the compressor discharge pipe and compare it to the refrigerant temperature at the condenser inlet.
- Symptom: If the temperature difference exceeds 5°C and approaches or surpasses 10°C, this is another sign of low refrigerant.
- Normal Condition: In normal systems, the temperatures at these points are very similar.
Confirming Low Refrigerant Levels
To confirm low refrigerant levels, all three key symptoms must be present:
- Electrical consumption below the regular value (RLA).
- High temperature difference between the evaporator inlet and outlet (>10°C or >15°C).
- Significant temperature difference between the compressor discharge and the condenser inlet (>5°C).
