When the water chiller works, there is a low-voltage fault. How to solve it?

Date:Jul 14, 2020

[China Refrigeration Network] Water chillers belong to industrial machinery and equipment. The development of science and technology has also made water chillers become intelligent. When water chillers fail, fault codes usually appear. Today, Cadelli analyzes and solves the low-pressure fault of water chillers.

What will be caused by low-voltage fault of water chiller?

1. Increased energy consumption

Because the compressor runs at low pressure and no load, the load of the motor will be reduced. Under the same refrigeration condition, the chiller with low pressure fault will waste power.

2. The cooling capacity becomes smaller

Because the suction pressure of water chillers becomes lower and the return air volume is less, the cooling capacity will not reach the target refrigeration, which will affect the normal use.

What are the reasons for the low pressure of water chillers? How to solve it?

No.1 refrigerant is insufficient or leaked

Insufficient refrigerant will lead to abnormal pressure in the system, resulting in lower suction pressure, low-pressure alarm of water chillers, equipment stop running, and the parts of refrigerant leakage can be diagnosed from the fittings pipe joints such as compressor, condenser, filter, expansion valve and evaporator, etc. After troubleshooting, it can be solved by filling a proper amount of refrigerant. If you don't know how to operate this process, you can contact the chiller manufacturer.

No.2 The outside temperature is low

The outside air temperature is low, and the cooling water starts running at low temperature; Or the refrigerating oil temperature is too low, and the refrigerator can not be completely separated, which will cause low-pressure fault. If the cooling water temperature is too low, shut down the cooling tower or throttle the cooling water to increase the cooling water temperature. If the temperature of refrigerating oil is too low, it can be solved by prolonging the preheating time of water chillers and raising the temperature of refrigerating oil to normal.

No.3 system pipeline is blocked

When assembling chillers, it is inevitable that impurities will penetrate into the system. After long-term use, all kinds of impurities will enter the system. At this time, the filter is blocked, the refrigerant throughput is reduced, and the return air volume is reduced, resulting in low-pressure failure.

Solution: Clean the filter, condenser and evaporator to ensure that the system is free from blockage, thus eliminating the low-pressure fault caused by the blockage of the system pipeline.

No.4 expansion valve is too small or damaged

Expansion valve is a throttling device of refrigeration system, too small will produce smaller refrigeration capacity, and too little refrigeration steam passing through throttling will cause the inlet pressure of compressor to decrease, resulting in low pressure failure.

Solution: properly increase the opening of expansion valve, or replace damaged expansion valve.

No.5 relay failure, electrical system false alarm

Relay plays the role of indirect protection equipment. Generally, the normal suction pressure of compressor is 0.4~0. 6MPa. When the suction pressure is lower than 0. 2MPa, it will cause the low-voltage protection relay to act, cut off the system circuit and stop the equipment. Sometimes, the low-voltage relay will work abnormally due to faults such as humidity and open circuit, and the system will report low voltage.

Solution: Check the low-voltage relay, repair or replace it. Non-technical personnel can contact the manufacturer for assistance.

Generally speaking, the low-voltage faults of chillers in normal use are caused by the above reasons. According to the system fault phenomena, step-by-step investigation is conducive to quickly finding the fault causes and resuming normal production as soon as possible. In case of low-voltage fault of water chiller, the water chiller manufacturer can be contacted for assistance.

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