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
- 72 -
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
- Refet 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
(N
2
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.
3
N
2
sealed parts.
Confirm N
2
Confirm air leaking
To protect
- In case of evaporator parts, if it doesn't
leak.
sounds when
moisture
noise when removing rubber cap blow
removing rubber
penetration.
dry air or N
2
gas for more than 1 min
cap.
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 200
L
Vacuum
EA
Use R134a
To protect
The rubber 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 weight the refrigerant at too hot or
exclusively.
with R12
too cold an area.(25°C is adequate.)
Weighing
refrigerant.
- Use copper bombe
allowance:±5g
Socket:2SV Plug: 2PV R134a
Note:Winter:-5g
Note:Do not burn O-ring (rubber) during
5g
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 by.
-The electronic leak detector is very
sensitive to halogen gas in the air. It also
can detect R141b in urethane. Please
practice, therfore, many times before use.
