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Causes And Solutions Of High Pressure Failures Of Chillers

Dec. 09, 2019

The high-pressure fault of the chiller means that the compressor exhaust pressure is too high, which causes the high-pressure protection relay to operate. The compressor discharge pressure reflects the condensing pressure. The normal value should be 1.4 ~ 1.8MPa, and the protection value setting is recommended not to exceed 2.0MPa. Because the long-term pressure is too high, it will cause the compressor to run too much current and burn the motor easily, causing damage to the compressor. So what are the factors that cause high-pressure faults in chiller units? Water Cooled Screw Chiller Supplier will come to tell you.


Water Cooled Screw Chiller


Water Cooled Screw Chiller


1. Too much refrigerant charge.

This situation generally occurs after maintenance, which is manifested by the high intake and exhaust pressures and equilibrium pressures, and the compressor running current is also relatively high.

Solution: The refrigerant should be discharged according to the suction and discharge pressure and the equilibrium pressure and the running current under normal conditions until normal.


2. The cooling water temperature is too high, and the condensation effect is poor.

The rated working condition of the cooling water required by the chiller is 30 ~ 35 ℃. The high water temperature and poor heat dissipation will inevitably lead to high condensation pressure. This phenomenon often occurs in high temperature seasons.

Solution: The cause of the high water temperature may be the failure of the cooling tower, such as the fan is not turned on or even reversed, and the water distributor does not turn. The amount of water is small. In this case, the temperature of the cooling water is generally maintained at a high level, which can be solved by increasing the storage tank.


3. The cooling water flow is insufficient to reach the rated water flow.

The main performance is that the pressure difference between the inlet and outlet of the unit becomes smaller (compared to the pressure difference at the beginning of the system's operation), and the temperature difference becomes larger.

Solution: The pipeline filter is clogged or too thin, and the water permeability is limited. You should choose a suitable filter and clean the filter regularly.


4. The condenser is fouled or blocked.

The condensed water is generally tap water, which is easy to scale at temperatures above 30 ° C. Since the cooling tower is open and directly exposed to the air, dust and foreign matter can easily enter the cooling water system, causing the condenser to be dirty and the heat exchange area small , Low efficiency, but also affect water flow. Its performance is that the pressure difference and temperature difference between the inlet and outlet water of the unit become larger, the temperature above and below the condenser is very high, and the copper tube from the condenser is hot.

Solution: The unit should be backwashed regularly and chemically cleaned and descaled if necessary.


5, false alarms caused by electrical faults.

Because the high-voltage protection relay is wet, has poor contact, or is damaged, the unit electronic board is wet or damaged, and a communication failure causes a false alarm.

Solution: For this kind of false fault, the HP fault indicator on the electronic board is not bright or light, manual resetting of the high-voltage protection relay is invalid, and the compressor running current is normal, and the suction and discharge pressure is normal.


6. Refrigerant is mixed with non-condensable gases such as air and nitrogen.

The refrigeration system has air. Many times the air will shake the pointer of the high pressure meter very much.

Solution: This situation usually occurs after maintenance, and the vacuum is not complete. After shutdown, the condenser can be evacuated or re-evacuated and added with refrigerant.


The above is the reason and solution for the high pressure failure of the chiller analyzed by the supplier of China Industrial Water Chiller, I hope to help everyone.

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