Air Source Screw Water Chiller Unit – Installation Operation and Maintenance Manual
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resistance, and resistance to ground) of the compressor are normal.
Cut off the power supply of the compressor and then turn on the main power supply.
Start the unit and check whether the switch between the star and delta AC contactors is normal (that is,
check the voltage between the three contacts is 380 V). (Because the power supply of the compressor
is cut off, the compressor is not powered on.)
Check whether there is an open phase (the voltage to the ground of each phase should be 220 V).
Check whether the onsite settings on the touchscreen conform to the requirements.
Check whether the expansion valve can be turned on or off properly (control the expansion valve
manually and check whether the step motor runs with normal operation voice).
Check whether the load/unload solenoid valve works properly by performing manual load/unload.
Check whether the oil heater of the compressor is in normal state and whether oil heating conditions
are met.
If all preceding items are normal, start the auxiliary devices and chilled water pump.
Cut off the main power supply and turn on the power supply of the compressor.
Turn on the main power supply again to start the unit.
7
.2 Commissioning Operations
Install a fluorine pressure gauge and a thermometer sensing probe on the unit and start the
compressor. Check whether the star and delta AC contactors are started and switched properly. Check
the voltage of the wiring at the bottom of each contactor.
Check the current of the compressor.
Check whether the fan runs properly and rotates in the correct direction. Then detect the operation
current.
Check whether the oil level is normal and whether the energy adjusting solenoid valve on the
compressor operates properly. (You can use a nonmagnetic blade to check whether the valve has
magnetism.)
Let the compressor run more than 20 minutes. During this process, check and monitor all operation
parameters, and observe the suction/discharge pressure of the unit.
Through the return air superheat, check whether the opening of the electronic expansion valve is in a
reasonable range.
After the unit enters working conditions, check whether the return air superheat of the unit is within the
range of 5–7. Check whether the discharge superheat and condensation subcooling are normal.
When the discharge temperature is high, check whether the solenoid valve and expansion valve on
the sparge pipe work properly. (You can use a nonmagnetic blade to check whether the valve has
magnetism.)
