LG LSSB2691ST Service Manual page 25

TROUBLE DIAGNOSIS
1-4. Practical Work For Heavy Repair
Items
1. Removal of residual
refrigerant.
2. Nitrogen blowing
welding.
3. Replacement of drier.
Compressor
Drain Pipe
Low pressure side
1) Continue to recover the refrigerant for more than 5 minutes after turning the refrigerator off.
2) Install a piercing type valve on the high pressure line (drier side). Then use the appropriate
recovery equipment to recover the refrigerant from the system. When the refrigerant has
been recovered, install a piercing type valve on the low pressure side. IT IS IMPORTANT
TO OPEN THE SYSTEM IN THIS ORDER TO KEEP THE OIL FROM BEING FORCED OUT.
The use of piercing type valves will allow future servicing and eliminates the possibility of a
defective pinch off.
Compressor
Drain Pipe
Low pressure side
When replacing a drier:
Weld and parts by blowing nitrogen (0.1~0.2kg/cm
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.
Filter
Inserting a capillary tube
Measure distance with a ruler and put a mark (12
mark and weld it.
Precautions
Evaporator
Evaporator
Hot Line
Drier
Condenser
High pressure side
Evaporator
Evaporator
Hot Line
Drier
Condenser
High pressure side
* Unit : mm
+3/-0 )on the capillary tube. Insert tube to the
25
3 way valve
KEY POINT
Observe the sequence for
removal of refrigerant.
(If not, compressor oil may
leak.)
3 way valve
KEY POINT
Welding without nitrogen
blowing produces oxidized
scales inside a pipe, which
affect the performance and
reliability.
2 ) to high pressure side after
KEY POINT
Be sure to check the
inserted length of capillary
tube when it is inserted.
(If inserted too far, the
capillary tube will be
blocked by the filter.)