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8.1.12 Refrigeration system
Determine whether refrigerant is needed by checking the value
of suction and discharge pressure and check whether there is a
leakage. Air tight test must be made if there is a leakage or parts
of refrigerating system is to be replaced. Take different measures
in the following two different conditions from refrigerant injection.
1) Total leakage of refrigerant. In case of such situation, leakage
detection must be made on the pressurized nitrogen used for the
system. If repair welding is needed, welding cannot be made
until all the gas in the 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. Refriger-
ant 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.
●
Connection must be renewed after injection is completed.
●
Never inject oxygen, acetylene or other flammable or poisonous
gas to the refrigeration system at leakage detection and air tight
test. Only pressurized nitrogen or refrigerant can be used.
CAUTION
8.1.13 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.
8.1.14 Auxiliary electric heater
When the ambient temperature is lower than 2
ć
, 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
ć
~10
ć
, the user may consider to use auxiliary
electric heater. Please refer to relevant professionals for the power
of auxiliary electric heater.
8.1.15 System antifreezing
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 antifreez-
ing.
1) If the unit that is shutdown for standby is placed in an
environment where the outdoor temperature is lower than 2
ć
, 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.
O&I manual
24
Summary of Contents for ICHS-420KC-5
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