LG GR-B277, Service Manual

Page: 103 / 134

TROUBLE DIAGNOSIS
- 103 -
Items Precautions
4. Vacuum degassing.
Pipe Connection
Connect the red hose to the high pressure side and the blue hose to the
low pressure side.
Vacuum Sequence
Open valves and and evacuate for 40 minutes. Close valve .
5. Refrigerant charging.
Charging sequence
1) Check the amount of refrigerant supplied to each model after completing vacuum
degassing.
2) Evacuate charging canister with a vacuum pump.
3) Measure the amount of refrigerant charged.
- Measure the weight of an evacuated charging canister with an electronic scale.
- Charge refrigerant into a charging canister and measure the weight. Calculate the weight
of refrigerant charged into the charging canister by subtracting the weight of an
evacuated charging canister.
KEY POINT
- If power is applied
during vacuum
degassing, vacuum
degassing shall be
more effective.
- Run the compressor
while charging the
system. It is easier
and works better.
KEY POINT
- Be sure to charge the
refrigerant at around
25°C [77°F].
- Be sure to keep -5g in
the winer and +5g in
summer.
the amount of refrigerant charged= weight after charging -
weight before charging (weight of an evacuated cylinder)
Calculation of amount of refrigerant charged
2 1
3
Compressor
Low
pressure
Condenser
High
pressure
Drier
Evaporator
Red
Yellow
Blue
Vacuum
Pump
Suction pipe
Hot Line
R134a
Indicate the weight of an
evacuated charging canister