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
- 61 -
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.
3N
2 sealed parts. Confirm N2 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 
Summer:+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.