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    Fresh Refrigeration Units Fresh Refrigeration Units May Cause A High Pressure Failure Jul 28, 2017

    Fresh Refrigeration Units Fresh refrigeration units may cause a high pressure failure

    Fresh refrigeration units may cause a high pressure failure

    Fresh refrigeration unit high pressure fault: compressor exhaust pressure is too high, resulting in high voltage protection relay action. Compressor exhaust pressure reflects the condensing pressure, the normal value should be 1.4 ~ 1.6MPa, the protection value is set to 2.0MPa. If the long-term pressure is too high, will lead to the compressor running current is too large, easy to burn the motor, but also easy to cause damage to the compressor exhaust valve.

    The reason for the high voltage failure is as follows:

    (1) the cooling water temperature is high, the condensation effect is bad. Chilled water unit requirements of the cooling water rated conditions in the 30 ~ 35 ℃, high water temperature, poor heat dissipation, will inevitably lead to high condensing pressure, this phenomenon often occurs in the hot season. The reason for the high water temperature may be: cooling tower failure, such as the fan is not open or even reverse, the water heater does not turn, the performance of the cooling water temperature is high, and rapid rise; outside the high temperature, short water, Less, the cooling water temperature is generally maintained at a high level, you can take the way to increase the reservoir to be resolved.

    (2) cooling water flow is insufficient, not up to rated water flow. The main performance is the industrial chiller group into and out of the water pressure difference is small (with the system put into operation at the beginning of the pressure difference), the temperature becomes larger. The reason for the lack of water flow is the lack of water or the presence of air in the system. The solution is to install the exhaust valve at the height of the pipe for exhaust. The pipe filter is clogged or used too well and the water permeability is limited. Suitable filters should be used and Regularly clean the filter; pump selection is small, and the system is not matched.

    (3) Condenser scaling or clogging. Condensate is generally used in tap water, it is easy to scale above 30 ℃, and because the cooling tower is open, directly exposed to the air, dust and foreign matter is easy to enter the cooling water system, causing the condenser dirty block, heat transfer area is small , Low efficiency, but also affect the water flow. Its performance is the unit out of water pressure difference, the temperature difference becomes big, hand touch the condenser up and down the temperature is very high, the condenser out of the copper tube hot. Should be regularly on the unit backwash, if necessary, chemical cleaning cleaning.

    (4) refrigerant charge too much. This situation generally occurs after the maintenance, the performance of the suction and exhaust pressure, the balance pressure is high, the compressor running current is also high. Should be in the rated conditions according to the suction and exhaust pressure and the balance of pressure and operating current deflation until normal.

    (5) refrigerant mixed with air, nitrogen and other non-condensable gas. This situation generally occurs after the repair, the vacuum is not complete. Can only be drained, re-vacuum, re-fill the refrigerant.

    (6) electrical errors caused by false positives. Due to high-voltage protection relay damp, poor contact or damage, unit electronic board damp or damaged, communication failure caused by false positives. This is a false fault, often on the electronic board HP fault indicator light or light, high-voltage protection relay manual reset is invalid, the computer displays "HP RESET", or automatically disappear, the compressor running current is normal, suction exhaust pressure normal.