1. Abnormal Compressor Noise

A healthy industrial chiller compressor normally runs with a stable and smooth operating sound.

Signs of possible compressor aging include:

• Continuous low-frequency humming;
• Metal friction sounds;
• Strong impact noise during start-up or shutdown;
• Noise increasing significantly under high load.

These symptoms may indicate:

• Bearing wear;
• Increased internal clearance;
• Valve plate or mechanical component damage.

Note: The clicking sound from electrical contactors is normal electrical operation and does not indicate compressor aging.

2. Reduced Cooling Performance

One of the most common signs of compressor aging is reduced refrigeration capacity.

Under the same conditions:

• Same ambient temperature;
• Same chilled water setting;
• Same production load;

if the chiller takes much longer to reach the target temperature, compressor efficiency should be checked.

Possible indicators include:

• Low discharge pressure;
• High suction pressure;
• Insufficient high-low pressure difference;
• Chilled water temperature unable to reach the set value.

Before judging compressor failure, always check refrigerant level, heat exchanger cleanliness, and water flow conditions.

3. Abnormal Current and Energy Consumption

Aging compressors often show increased energy consumption.

Typical symptoms:

• Operating current higher than the rated value;
• Higher power consumption for the same cooling output;
• Excessive current even under low-load conditions.

This usually means the compressor requires more electrical energy to produce the same refrigeration capacity.

For plastic processing factories running injection molding machines continuously, compressor efficiency directly affects long-term operating costs.