Industrial Chiller – Common Faults and Troubleshooting Guide
Industrial chillers may experience faults related to the refrigeration system, water circulation system, electrical control system, or heat dissipation system. The following table provides common problems, possible causes, inspection methods, and recommended solutions.
| Fault / Symptom | Possible Causes | Inspection | Recommended Solution |
|---|---|---|---|
| High-Pressure Alarm | Dirty condenser, high ambient temperature, condenser fan failure, insufficient cooling water, excessive refrigerant charge | Check high-pressure reading, condenser fan, cooling-water flow and condenser condition | Clean the condenser; check or replace the fan/pump; improve ventilation; check refrigerant charge |
| Low-Pressure Alarm | Low refrigerant level, expansion valve blockage, evaporator icing, clogged filter | Check low-pressure reading, frosting condition and filter | Find and repair leaks; recharge refrigerant according to specifications; clean or replace the filter; check the expansion valve |
| Compressor Does Not Start | Power failure, incorrect phase sequence, overload protection, pressure protection, contactor failure | Check three-phase voltage, alarm code, contactor and protection devices | Restore power; correct phase sequence; check protection devices and contactor; reset after the fault is eliminated |
| Compressor Overload | Abnormal voltage, compressor mechanical problem, excessive condensing pressure, frequent starting | Measure operating current and voltage | Check power supply; reduce condensing pressure; inspect the compressor |
| Outlet Water Temperature Cannot Reach Setpoint | Insufficient cooling capacity, excessive water flow, dirty heat exchanger, high ambient temperature | Check inlet/outlet water temperature, water flow and pressure | Adjust water flow; clean the heat exchanger; inspect the refrigeration system |
| Outlet Water Temperature Too Low / Icing | Insufficient water flow, temperature-control failure, temperature set too low, expansion valve problem | Check pump, water flow and temperature sensor | Increase water flow; check the temperature sensor; adjust the temperature setting |
| Water Pump Does Not Run | Motor failure, phase loss, overload, blocked impeller | Check voltage, current and pump condition | Check the motor and electrical circuit; clean the impeller; repair or replace the pump if necessary |
| Water Flow Alarm | Low water level, blocked piping, clogged filter, water pump failure | Check tank water level, pressure, flow switch and pump | Add water; clean the filter; check the pump and piping |
| Unstable Water Temperature | Unstable water flow, incorrect temperature-control parameters, fluctuating cooling load | Monitor water temperature and flow rate | Stabilize water flow; optimize control parameters; check the temperature sensor |
| Frequent Start/Stop | Temperature differential set too small, low cooling load, faulty temperature sensor | Check operating cycle and temperature settings | Increase the temperature differential; check the temperature sensor; optimize control settings |
| Poor Heat Dissipation – Air-Cooled Chiller | Dirty condenser fins, fan failure, insufficient ventilation space | Check condenser fins, fans and airflow | Clean condenser fins; repair/replace the fan; ensure sufficient ventilation space |
| Abnormal Noise or Vibration | Fan/pump bearing wear, compressor problem, loose or vibrating pipes | Identify the source of noise or vibration | Replace damaged bearings/fans; inspect the compressor; secure the piping |
| Refrigerant Leakage | Leaking brazed joints, vibration damage, defective valve seals | Perform pressure testing and leak detection | Repair the leak; evacuate the system; recharge refrigerant according to specifications |
| Electrical Cabinet Overheating | Cooling fan failure, excessive dust, high ambient temperature | Check cabinet temperature, cooling fan and internal dust | Clean the cabinet; replace the cooling fan; improve cabinet ventilation |
Recommended Troubleshooting Sequence
When troubleshooting an industrial chiller, it is recommended to follow this sequence:
1. Check the alarm code
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2. Check the power supply
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3. Check the water circulation system
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4. Check the high and low refrigerant pressures
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5. Check the refrigerant charge and possible leaks
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6. Check the compressor
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7. Check sensors, controllers and electrical components
Important Service Note
When a high-pressure or low-pressure alarm occurs, do not simply add refrigerant.
First determine the actual cause of the abnormal pressure. Incorrect refrigerant charging may cause poor cooling performance, excessive compressor load, icing, or even compressor damage.
Quick Diagnosis
High Pressure + High Condensing Pressure
- Dirty condenser
- Condenser fan failure
- Insufficient cooling-water flow
- High ambient temperature
- Excessive refrigerant charge
Low Pressure + Low Suction Pressure
- Insufficient refrigerant
- Insufficient evaporator water flow
- Clogged filter
- Expansion valve malfunction
- Evaporator icing
High Compressor Current
- Excessive condensing pressure
- Abnormal power supply
- Compressor mechanical failure
- Refrigeration system abnormality
