Cooling Cycle Heavy Repair - LG GR-B197GVQ Service Manual

3.
Cooling Cycle Heavy Repair
3-1. The
Heavy Repair
Standards for
Refrigerator
with R134a
Refrigerant
NOTE)
Please
contact Songso
company on
+82-53-554-2067 if you have
inquiry
on
heavy repair special facility.
TROUBLE DIAGNOSIS
-93-
NO. Items Unit Standards
Purposes
Remarks
1
Pipe
and
piping
Min.
Pipe:within
1 hour. To
protect
The
opening
time should be reduced
to
a
system
opening
time.
Comp:within
Moisture half of the standards
during
rain and
10 minutes. Penetration. rainy
seasons
(the penetration of water
Drier:within into the pipe is dangerous).
20 minutes.
2 Welding. Nitrogen Weld under To
protect
-
Refer to repair note
in each
part.
Pressure. Nitrogen oxide scale
-
R134a refrigerant is
more
susceptible to
atmosphere formation. leaks than R12 and requires
more care
(N2
pressure:
during welding.
0.1~0.2
kg/cm
2
)
-
Do
not apply
force
to pipes
before and
after
welding to
protect
pipe
from
cracking.
3N
2
sealed
parts.
Confirm N2 Confirm air
leaking
To
protect
-
In
case
of
evaporator parts,
if it doesn't
leak. sounds when moisture make noise when
removing bushing
removing bushing penetration.
cap blow
dry
air
or
N2 gas for
more
cap.
than 1 min
use
the
parts.
Sound:usable
No sound:not usable
4 Refrigeration Evacuation
Min.
More than To
remove
Cycle. time 40 minutes. moisture.
Vacuum Torr Below 0.03
(ref) Note:Only applicable to
the model
degree equipped with
reverse
flow
protect
plate.
Vacuum EA
High
and low Vaccum
efficiency
can
be
improved by
Pressure sides
are
operating
compressor
during
evacuation.
evacuated at the
same
time for
models above 200L
Vacuum EA Use R134a To
protect
The bushing pipes for R12 refrigerant shall
piping
exclusive
mixing
of be melted when
they
are
used for R134a
manifold. mineral and
refrigerant
causes
of leak.
ester
oils.
Pipe
EA Use R134a To
protect
coupler
cxclusive. R12 Refri-
gerant
mixing.
Outlet R134a exclusive.
˝
(Socket)
Plug R134a exclusive
˝
5 Refrigerant weighing.
EA Use R134a Do
not
mix
-
Do
not weigh
the
refrigerant at too
hot
or
exclusively.
with R12
too cold
an
area.(25°C is adequate.)
Weighing refrigerant.
-
Use copper charging cannister.
allowance: ±5 g Socket:2SV
Plug:
2PV R134a
Note:Winter: -5 g Do
not
mix Note:Do
not
burn
O-ring (bushing) during
Summer: +5 g
refrigeromts. welding.
6 Drier
replacement.
-Use R134a
exclusively
To
remove
for R134a
refrigerator
the moisture
-Use R12
exclusively
from
pipe.
for R12
refrigerator
-Replace
drier whenever
repairing refrigerator
cycle piping.
7 Leak check. -Do
not
use soapy
Detect -Check oil leak
at refrigerant
leak
area.
water for check. refrigerant
Use electronic leak detector if oil leak is
it may be sucked leak
area.
not found.
into the
pipe.
-The electronic leak detector is very
sensitive
to halogen
gas in the air. It also
can
detect R141b in urethane. Please
practice,
the
refore,
many times before
use.