Chiller is widely used in pharmacy, chemical industry, laboratory and industry. The compressor is an important part in the operation of the chiller. The pressure of compressor changes and in-machine protection occur for a variety of reasons. In-machine protect is the thermal switch inside the compressor disconnects the power supply when the temperature of the compressor exceeds the setting value. It can be switched on and continue working until the compressor cools down. The main reasons and solutions are described below.
- Compressor suction pressure is too low will led to compressor protection,and lead to low suction pressure for the following reasons.
When the refrigerant is insufficient, the compressor overheat and cause its overall heating. The thermal switch is triggered, generating the compressor heat protection. At this point, check the pipe connection for leaks and fill the refrigerator after repair.
When the expansion valve opens over small or blocked resulting in the refrigerator pipe blocked. At this time, the expansion valve should be properly reduced opening degree, after the removal of high and low maintenance automatic calibration.
When the filter is blocked or the cooler has too much copper scale, the pipe diameter is reduced and the water yield is insufficient. As a result, the heat dissipation becomes worse and the compressor temperature drops slowly, resulting in internal protection. The filter should be removes and replace or the copper tube of the cooler should be cleaned.
- When the condensing temperature in the compressor rises, the condensing pressure rises and is detected as high exhaust pressure. With the increase of exhaust pressure, the exhaust temperature will also rise, which will cause the compressor to overheat and internal protection. The following factors will cause the condensation temperature to rise.
When the cooling water or ambient temperature rises, or when the flow rate of the cooling medium is small, the condensation temperature will rise directly. If the circulation flow is too large, the condensation heat load will increases. A large amount of heat cannot be removed in time, resulting in an increase in condensation temperature. If there is too much refrigerant filling, the excess refrigerant will occupy a part of the condensing tube and reduce the condensing area, causing the condensing temperature to rise.
When the compressor is protected internally because the condensing pressure is too high, the condenser should be cleaned in time or the cooling water flow pressure should be increased.
- When the cold water machine size does not match, especially when it is too small, the chiller will never reach the setting temperature. The compressor will works until it is thermal protected. The chiller should be selected again to ensure that the chiller can reach the set temperature.