Hitachi Set Free mini-HNRQ1 Series, Service Manual

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INSTALLATION
(4) Record of Additional Charge
The total refrigerant charge of the system should be calculated by the following formula:
Total of Refrigerant Charge = W + W
0
The system = + = kg
3.8 Additional Refrigerant Charge Work
(1) The additional refrigerant charge is required according to the calculation.
(2) Before charge work, make sure that the stop valves are fully closed.
(3) Charge the additional refrigerant from the check joint of liquid stop valve.
(4) After refrigerant has been charged, fully open the liquid stop valve and gas stop valve.
(5) If it proves impossible to charge the required quantity of refrigerant, follow the procedure below:
(A) Fully open the gas stop valve.
(B) Operate the compressor in the cooling mode and charge the additional refrigerant from the check
joint of the liquid stop valve. At this time, keep the liquid stop valve slightly open.
(C) After the refrigerant is charged, fully open the liquid stop valve and the gas stop valve.
(D) Carefully calculate any additional refrigerant quantity for charging. If the quantity of additional refrigerant
is not correct, it may cause an abnormal condition in the system. The additional refrigerant must be
charged as liquid.
●
Do not apply excessive force to the stop valves after fully opening the valves.
●
At the test run, fully open the gas and liquid stop valves.
Total Additional Charge: W Kg
Total Ref. Charge: Kg
Date of Ref. Charge Work: / /
NOTICE