Hitachi SAMURAI Series Service Manual page 74

3 Servicing
Cycle components
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Replacement of oil inside compressor
To replace the oil of the compressor proceed as explained below:
1 Collect all refrigerant into a condenser before this work. Recover the rest of refrigerant from the water cooler and the
compressor.
2 With a module capacity of 50~75%, perform the operation ensured by suction gas superheat for about 10 minutes,
and after recovering the refrigerant as explained in
turn power off and perform the following operation.
3 Oil extraction work
Remove the plugs for oil extraction (A-B) at 2 places in screw compressor, and measure the amount of extracted oil.
It is not possible to extract the oil from the inside of compressor by just removing one plug, so always remove the 2
plugs.
4 Check of oil strainer
Remove the oil strainer cover (C), and confirm the state of the internal oil strainer. In case of finding any abnormality
such as dirt or any damage, clean or replace the part as adequate.
5 Oil charge work
Attach the oil strainer, the oil strainer cover (C) and the oil extraction plugs (A-B). Connect the charge hose to the
check joint (Discharge pressure outlet). Let the oil be absorbed by the charge hose while performing vacuum from the
check joint of the suction side. (Charge the amount of oil that had been extracted in the above point "Oil extraction
work")
6 After completing the operation, perform vacuum again and charge refrigerant (check in the Installation and Operation
Manual, chapter).
Maintenance
?
N O T E
• Use a clean charge hose.
• In order to avoid absorption of atmospheric moisture by refrigerant oil, use a container with a small opening and complete the
operation in the shortest time possible (within 20 minutes as a criterion).
Refrigerant gas suction inlet (65A)
Check joint (Suction pressure release)
(1/4 flare nut)
66 SMGB0120 rev.0 - 11/2017
Recovery of refrigerant
Refrigerant gas discharge outlet (50A)
Oil
Oil extraction
level
Oil heater
(3/8 plug)
gauge
Oil strainer cover
in the Installation and Operation manual,
Check joint (Discharge pressure release)
(1/4 flare nut)
Check joint (100% detection hole)
(1/4 flare nut)
Oil extraction
(1/4 plug)