Midea MCCDH30A-TA3SL, Техническое и сервисное руководство

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Air-cooled modular chiller unit
1
system is discharged. Before injecting refrigerant, the whole refrigeration system must be completely dry
and of vacuum pumping.
● Connect vacuum pumping pipe at the fluoride nozzle at low-pressure side.
● Remove air from the system pipe with vacuum pump. The vacuum pumping lasts for above 3 hours.
Confirm that the indication pressure in dial gauge is within the specified scope.
When the degree of vacuum is reached, inject refrigerant into the refrigeration system with refrigerant bottle.
Appropriate amount of refrigerant for injection has been indicated on the nameplate and the table of main
technical parameters. Refrigerant must be injected from the low pressure side of system.
● The injection amount of refrigerant will be affected by the ambient temperature. If the required amount has
not been reached but no more injection can be done, make the chilled water circulate and start up the unit
for injection. Make the low pressure switch temporarily short circuit if necessary.
2) Refrigerant supplement. Connect refrigerant injection bottle on the fluoride nozzle at low-pressure side
and connect pressure gauge at low pressure side.
● Make chilled water circulate and start up unit, and make the low pressure control switch short circuit if
necessary.
● Slowly inject refrigerant into the system and check suction and discharge pressure.
Disassembling compressor
Follow the following procedures if compressor needs to be disassembled:
1) Cut off the power supply of unit.
2) Remove power source connection wire of compressor.
3) Remove suction and discharge pipes of compressor.
4) Remove fastening screw of compressor.
5) Move the compressor.
Auxiliary electric heater
When the ambient temperature is lower than 2
℃
, the heating efficiency decreases with the decline of the
outdoor temperature. In order to make the air-cooled heat pump stably run in a relatively cold region and
supplement some heat lost due to de-frosting. When the lowest ambient temperature in the user‟s region in
winter is within 0 C~10 C, the user may consider to use auxiliary electric heater. Please refer to relevant
professionals for the power of auxiliary electric heater.
System anti-freezing
In case of freezing at the water-side heat exchanger interval channel, severe damage may be caused, i.e.
heat exchange may be broken and appears leakage. This damage of frost crack is not within the warranty
scope, so attention must be paid to anti-freezing.
1) If the unit that is shut down for standby is placed in an environment where the outdoor temperature is
lower than 0 C, the water in the water system should be drained.
2) Water pipe may be frozen when the chilled water target flow controller and anti-freezing temperature
senor become ineffective at running, therefore, the target flow controller must be connected in accordance
with the connection diagram.
3) Frost crack may happen to water-side heat exchanger at maintenance when refrigerant is injected to the
unit or is discharged for repair. Pipe freezing is likely to happen any time when the pressure of refrigerant is
below 0.4Mpa. Therefore, the water in the heat exchanger must be kept flowing or be thoroughly discharged.