LG MULTI V 5 Manual Book page 77

2.3 Checking Method (Flow Chart)
Checking start
After starting, high
No
and low pressure difference is
occur?
Yes
The connection
direction of the 3-phase power
supply is correct?
Yes
Signal is applied
successfully on the PCB?
Yes
Current value is normal
No
when compressor
All direction of 4 way valve
operating?
is correct?
Yes
Yes
Replacing compressor
Restart
After starting, high
and low pressure difference is
occur?
No malfunction of compressor
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Re-connection of terminal or
No
change the direction of power
supply
No
Replacing PCB
No
Replacing 4way valve
No
Replacing compressor
2.4 Process of Replacing the Compressor
Please follow the below process when you replace the compressor.
· Before replacing the compressor, check whether the failure of the compressor.
· Change the oil for compressor after replacing the compressor for 2~3 times.
1. check the turn off sign of the main power supply.
2. Remove the refrigerant with manifold gauge connecting to service valve.
Caution
Please release gradually the refrigerant, because there may be released oil mixed
with the refrigerant.
3. Remove the terminal cover of compressor and power supply cable.
4. Please remove the crank case heater and discharge temperature sensor of the compressor.
5. Please remove the mounting nut of the compressor.
6. Please be separated by heating the welded portion of the pipe connected to the compressor.
7. Replace the compressor.
8. Please reconnect the pipe that had been separated by #7 to compressor by welding.
9. After closing the service valve of liquid pipe & gas pipe,
check whether there is a site of the leak by injecting nitrogen gas(38 kgf/cm²g) through the
check joint of the high-pressure side and low pressure side.
10. Remove the nitrogen gas.
11. Open the service valve (liquid pipe and gas pipe) of the outdoor unit and make a vacuum.
12. Please install the insulation material and the discharge temperature sensor of compressor.
13. Connect power supply cable to terminal of compressor.
Caution
Please be aware that not occur the reverse phase & loss of phase when connecting
the phase.
14. After complete of vacuum processing, please charge the refrigerant by calculating the additional
amount of refrigerant according refrigerant basic amount of the enclosed, outdoor unit charging
factor, the pipe length.
15. After confirming once again of the power supply line connection is correct to the terminals of the
compressor, please check the insulation resistance. Please make sure that you cover the com-
pressor terminal cover, turn on the power, and check the current flows through the crankcase
heater.
16. Make sure that the service valve of liquid pipe side and gas pipe side has been opened.
17. Please check the operation status after operating all IDU.
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