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Common Error In Screw Water Chiller

Nov 03, 2017

Common Error in Screw Water Chiller


1. Screw chiller communication failure


Computer control of the various modules through the communication line and the total interface board to achieve, resulting in communication failure is the main reason for poor communication or open circuit lines, especially the interface damp oxidation caused by poor contact, the other electronic board or the interface Board failure, the address DIP switch selection improper, power failure can cause communication failure.


2. Screw chillers low pressure failure


Compressor suction pressure is too low, resulting in low-voltage protection relay action. 2MPa. Compressor suction pressure reflects the evaporation pressure, the normal value should be 0.4 ~ 0. 6MPa, the protection value is set to 0. 2MPa. Inspiratory pressure is low, the return air less, less cooling capacity, resulting in a waste of energy, for the back to the compressor cooling motor cooling poor, easy to damage the motor.


3. Screw chillers high pressure failure


Compressor exhaust pressure is too high, resulting in high voltage protection relay action. Compressor discharge 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.


4. Screw chiller compressor overheating failure


Compressor motor winding embedded thermistor, the resistance is generally 1kΩ. Winding overheating, the resistance will rapidly increase, more than 141kΩ, the thermal protection module SSM action, cut off the unit operation, while displaying overheating fault, TH fault indicator light.


5. Screw chiller low temperature valve failure


Expansion valve outlet temperature reflects the evaporation temperature is a factor that affects the heat transfer, the general temperature difference between it and the refrigerant water 5 ~ 6 ℃. When the valve temperature failure occurs, the compressor will shut down, when the valve temperature rise, automatically resume operation, the protection of -2 ℃.