LG GR-B197GVQ Service Manual page 96

3-4. Practical Work For
Heavy Repair
TROUBLE DIAGNOSIS
-96-
Items Precautions
1. Removal of residual
refrigerant.
1)
Remove residual
refrigerant
more
than 5 minutes later after
turning
off the
refrigerator.
(
If
not,
compressor oil may leak
inside.)
2)
Remove retained
refrigerant slowly by cutting
first
high
pressure side
(drier part)
with
a
nipper
and then
cut
low pressure side.
2. Nitrogen blowing
welding.
When
replacing
a
drier:
Weld and
parts
by blowing nitrogen(0.1~0.2kg/cm
2
) to high
pressure side after
assembling
a
drier.
When
replacing
a
compressor:
Weld and
parts
by blowing nitrogen to
the low pressure side.
Note)
For other
parts,
nitrogen blowing
is
not
necessary because it does
not produce
oxidized
scales inside pipe because of its short welding time.
3.
Replacement
of drier.
Inserting
a
capillary
tube
Measure distance with
a
ruler and
put
a
mark(12
+3/-0
)on
the
capillary
tube. Insert tube
to
the
mark and weld it
KEYPOINTING
Observe the sequence for
removal of
refrigerant.
(If
not,
compressor oil may
leak.)
KEYPOINTING
Welding
without
nitrogen
blowing produces
oxidized
scales inside
a
pipe, which
affect
on
performance
and
reliability
of
a
product.
KEYPOINTING
Be
sure
to
check the
inserted
length
of
capillary
tube when it is inserted.
(If
too much inserted
a
capillary
tube is blocked
by
a
filter.)
Compressor
Low pressure side
Condenser
High pressure side
Drier
Evaporator
Release
Refrigent
Intake
Suction
1 2 1
2
Evaporator
Drier
High pressure side
Condenser
Refrigent
Intake
12
+3
-0
Filter
*Unit:mm