Inspection of compressor and refrigerant piping system of screw type industrial chiller

Screw-type industrial chillers check whether the oil level in the compressor is normal. The normal compressor oil level is generally in the middle of the sight glass. Check whether the coil of the compressor capacity adjustment solenoid valve is locked, and whether the capacity adjustment capillary tube is damaged. All refrigerant valves in the refrigeration system (angle valve at the outlet of the condenser, compressor suction and discharge stop valves) are in an open state, so that the refrigerant system is unblocked. Check the high and low pressure values, whether the high and low pressure setting values of the pressure relay are normal (the high pressure setting value is 1.8 MPa, the low pressure setting value is 0.2 MPa, and the user is not allowed to change it without authorization).

    Screw-type industrial chillers check whether the compressor lubricating oil has been preheated for more than 8 hours. The oil heater is energized and heated for at least 8 hours before the test run to prevent the refrigerating oil from foaming during startup. If the ambient temperature is low, the oil heating time needs to be relatively longer. When starting at a low temperature, due to the high viscosity of the lubricating oil, it may be difficult to start and the compressor may be loaded and unloaded. Generally, the lubricating oil temperature must be at least 23°C to operate. Check whether the compressor wiring is correct. After the compressor is started, shut down immediately and observe the instantaneous system pressure change to ensure that the discharge pressure rises and the return pressure drops. On the contrary, the compressor is reversed and the wiring sequence of the compressor needs to be readjusted.

    The screw-type industrial chiller should be tested and run with the main circuit disconnected to check whether the sequence of actions is normal. The normal starting sequence is: turn on the power, press the unit start button three minutes, the star AC contactor is closed, after a short time, the star AC contactor is disconnected, the delta AC contactor is closed, and the unit starts to start The load value starts and loads gradually.