LG REFRIGERATOR, Service Manual

Page: 16 / 69

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NO. ITEMS UNIT STANDARDS PURPOSES REMARKS
General Control of Refrigerating Cycle
Pipe and
piping system
opening time
Welding
N
2
sealed
parts
Refrige-
ration
Cycle
Refrigerant
weighing
Drier
replacement
1
Leak check
2
3
4
5
6
Min.
7
Nitrogen
pressure
Confirm
N
2
leak
Min.
Torr
EA
EA
EA
EA
Pipe: within 1 hour.
Comp: within 10 minutes.
Drier: within 20 minutes.
Weld under Nitrogen
atmosphere.
(N
2
pressure:
0.1~0.2 kg/cm
2
)
Confirm the sound of
pressure relief when
removing the rubber cap.
Sound: usable
No sound: not usable
More than 40 minutes
Below 0.03 (ref)
High and low pressure sides
are evacuated at the same
time for models above 200
l .
Use R-134a manifold
exclusively.
Use R-134a manifold
exclusively.
R-134a manifold exclusively.
R-134a manifold exclusively.
Use R-134a exclusively.
Weighing allowance: 5g
Note: Winter: -5g
Summer: +5g
- Use R-134a exclusively for
R-134a refrigerator.
- Replace drier whenever repairing
refrigerator cycle piping.
- Do not use soapy water for
check. It may be sucked
into the pipe by a vacuum.
To protect
moisture
penetration.
To protect oxide
scale formation.
To protect
moisture
penetration.
To remove moisture.
To protect mixing
of mineral and
ester oils.
To protect R-12
refrigerant mixing.
To protect R-12
refrigerant mixing.
To protect R-12
refrigerant mixing.
Do not mix with
R-12 refrigerant.
To remove the
moisture from
pipe inside.
Defect in
refrigerant leak
area.
The opening time should be reduced
to a half of the standards during rain
and rainy seasons (the penetration of
water into the pipe is dangerous).
- Refer to repair note in each part.
- R-134a refrigerant is more
susceptible to leaks than R-12 and
requires more care during welding.
- Do not apply force to pipes before and
after welding to protect pipe from cracking.
- In case of evaporator parts, if it doesn't
make sound when removing rubber
cap, blow dry air or N
2
gas for more
than 1 min. and than use the parts.
Note: Only applicable to the model
equipped with reverse flow
protect plate.
Vacuum efficiency can be improved
by operating compressor during
evacuation.
The rubber pipes for R-12 refrigerant
will be melted when they are used for
R-134a refrigerant (causes of leak.)
- Do not weigh the refrigerant at too
hot or too cold an area.
(77°F [25°C] is adequate.)
- Make Copper charging canister
(Device filling refrigerant)
Socket: 2SV Plug: 2PV R-134a
Note: Do not burn O-ring (bushing)
during welding.
- Check for an oil leak at the refrigerant
leak area. Use an electronic leak
detector if an oil leak is not found.
- The electronic leak detector is very
sensitive to halogen gas in the air. It
also can detect R-141b in urethane.
Practice many times before using this
type of detector to avoid false readings.