LG LSC27910SB/01, Service Manual

Page: 77 / 97

3. Sealed System Heavy Repair
3-1. The Heavy Repair Standards for Refrigerator with R134a Refrigerant
No. Items Unit Standards Purposes Remarks
1
Pipe and piping system
opening time
Min
Pipe: Within 1 hour
Comp: Within 10 min
Drier: Within 20 min
To protect moisture penetration
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.
R134a refrigerant is more susceptible to leaks
than R12 and requires more care during
welding.
Do not apply force to pipes before and after
welding to protect pipe from cracking.
3 N2 Sealed parts Leak
Sounds while removing
bushing cap. Sound:
usable No sound:Not
usable
To protect moisture penetration
In case of evaporator parts, if it does not make
noise when removing bushing cap blow dry air
or N2 gas for more than 1 min use the parts.
Refrigeration cycle
Evacuation time
Min. More than 40 min To remove moisture
Vacuum degree Torr Below 0.5 (ref)
Only applicable to the model equipped with
reverse flow protect plate.
Vacuum EA
High and low pressure
side evacuates at the
same time for models
above 200 l
Vacuum eficiency can be improved by operating
compressor during evacuation
Vacuum piping EA
Use R134a exclusive
manifold
To protect mixing or mineral and
ester oils
The bushing pipes for R12 refrigerant shall be
melted when they are used for R134a refrigerant
causes of leak.
Pipe couple EA
Use R134a exclusive
manifold
To protect R12 Refrigerant mixing
Outlet (Socket) R134 exclusive
Plug R134 exclusive
Do not weigh the refrigerant at too hot or too
cold an areas (25°C (77°F) is adeqate)
Use copper charging canister
Socket. 2SV Plug: 2PV R134a
Note: Do not burn O-ring (rubber) during
welding
Use R134a exclusive
and remove for R134a
refrigerant moisture
Replace drier whenever
from pipe repairing
refrigerator cycle
piping.
Check oil leak at refrigerant leak area.
Use electronic leak detector if oil leak is not
found
The electronic leak detector is very sensitive to
halogen gas in there. It also can detect R141b
in urethane. Please practice therefore many
times before use.
2
Do not mix with R12 refrigerant
Use R134a exclusived
weighing allownce ±5g.
Note: Winter: ±5g.
Summer: ±5g
EA Refrigerant weighing 5
To protect oxide scale formation
Weld under nitrogen
atmospher (N2
pressure 0.1~ 0.2
kg/cm2)
Nitrogen
Pressure
Welding
Leak check 7 Detect refrigerant leak area
Do not use soapy water
for check. It may be
sucked into the pipe.
Drier replacement 6
- 76 -
https://appliancetechmanuals.com