Household Unit Technical Service Manual
40
suction pipe fall out from the compressor suction port.
(5)
Put the compressor upright and then remove the other rubber plugs. Immediately weld the connecting
pipe. Firstly, weld the exhaust pipe and then the suction pipe. After removing the rubber plug, do not put
the compressor for a long period, otherwise the moisture may invade into the pipe. When welding the
pipes, make sure to charge nitrogen to a pressure of 1.0~3.0kgf/cm2.
(6)
Restore the compressor to the state before replacement of the compressor
z
After installing the power cables of the compressor, energize and inch start the compressor to
check if it rotates in reverse direction. (If rotating in reverse direction, the compressor will give out
depressing sounds).
z
In event the lubricating oil leaks, please add immediately.
Note: Generally, the exhaust pipe of the unit is relatively thin. And in order to reduce the transfer of vibration,
the exhaust pipe is designed of one U-type bend at least. Therefore, the exhaust pipe may vibrate to some
extent. You may cut off the exhaust pipe before removing the suction pipe by shaking the compressor.
4.5.3 Treatment of Leakage in System Pipeline
The highly air tightness of the system pipeline is the top importance as well as the priority to ensure the
reliable and stable operation of the system. The leakage of refrigerant will not only affect the normal
operation of the unit directly, but also cause pollution to the environment. In event of open fire, the refrigerant
will decompose into poisonous gas which causes severe harm to the living beings. In event leakage, please
immediately stop the unit for detection and repair of the leakage.
Operating Steps:
(1) Charge nitrogen 20.0kgf/cm
2
into the system pipeline.
(2) Use soap water to check the connection between the pipes. Mark properly if finding leakage.
(3) After completing the detection of the entire pipeline, charge nitrogen again 1.0~3.0kgf/cm
2
to weld
the leaking point.
(4) After repairing the leakage, charge high-pressure nitrogen (25.0kgf/cm
2
). Check the readings on
pressure gauge after 48 hours. The pressure drop as computed below shall not be 1% higher than
the test pressure. Otherwise, the cause shall be found out and the leakage shall be repaired until it
is retested acceptable.
Δ
P=P1-P2 (273+T1)/(273+T2)
In which:
Δ
P – Pressure drop (MPa)
P1, P2 – Nitrogen pressure at the start and end of the test (MPa)
T1, T2 – Nitrogen temperature at the start and end of the test ( )
If permitted, it is best to use the halogen leakage detector upon initial finding of refrigerant leakage.
4.5.4 Vacuuming of System Pipeline after Repair
The vacuum level of the system pipeline will directly affect the normal operation of the unit. Low vacuum
level may result in abnormal rise of the system high pressure, thus increasing the power consumption or
even damaging the compressor. Therefore, after nitrogen-filled leakage detection, stringent vacuuming shall
be carried out to the system.
Operating Steps:
