General Control of Refrigerating Cycle
- 16 -
NO.
ITEMS
UNIT
STANDARDS
PURPOSES
REMARKS
Pipe and
piping system
opening time
Welding
N
2
sealed
parts
Refrige-
ration
Cycle
Refrigerant
weighing
Drier
replacement
Leak check
1
2
3
4
5
6
7
Min.
Nitrogen
pressure
Confirm
N
2
leak
Min.
Torr
EA
EA
EA
EA
Pipe: within 1 hour.
Comp: within 10 minutes.
Drier: within 20 minutes.
Weld under Nitrogen
atmosphere.
(N
2
pressure:
0.1~0.2 kg/cm
2
)
Confirm air leaking sounds
when removing rubber cap.
Sound: usable
No sound: not usable
More than 40 minutes
Below 0.03 (ref)
High and low pressure sides
are evacuated at the same
time for models above 200
l
.
Use R-134a exclusive
manifold.
Use R-134a exclusive.
R-134a exclusive.
R-134a exclusive.
Use R-134a exclusively.
Weighing allowance: 5g
Note: Winter: -5g
Summer: +5g
- Use R-134a exclusively for
R-134a refrigerator.
- Use R-12 exclusively for
R-12 refrigerator.
- Replace drier whenever repairing
refrigerator cycle piping.
To protect
moisture
penetration.
To protect oxide
scale formation.
To protect
moisture
penetration.
- Do not use soapy water for
check. It may be sucked
into the pipe by vacuum.
To remove moisture.
To protect mixing
of mineral and
ester oils.
To protect R-12
refrigerant mixing.
"
"
Do not mix with
R-12 refrigerant.
To remove the
moisture from
pipe inside.
Defect
refrigerant leak
area.
The opening time should be reduced
to a half of the standards during rain
and rainy seasons (the penetration of
water into the pipe is dangerous).
- Refer to repair note in each part.
- R-134a refrigerant is more
susceptible to leaks than R-12 and
requires more care during welding.
- Do not apply force to pipes before and
after welding to protect pipe from cracking.
- In case of evaporator parts, if it
doesn't make sound when removing
rubber cap, blow dry air or N
2
gas for
more than 1 min and use the parts.
Note: Only applicable to the model
equipped with reverse flow
protect plate.
Vacuum efficiency can be improved
by operating compressor during
evacuation.
The rubber pipes for R-12 refrigerant
shall be melted when they are used for
R-134a refrigerant (causes of leak).
- Do not weigh the refrigerant at too
hot or too cold an area.
(77 F[25 C] is adequate.)
- Make Copper bombe
Socket: 2SV Plug: 2PV R-134a
Note: Do not burn O-ring (rubber)
during welding.
- Check oil leak at refrigerant leak
area. Use electronic leak detector if
oil leak is not found.
- The electronic leak detector is very
sensitive to halogen gas in the air. It
also can detect R-141b in urethane.
Please practice, therefore, many
times before use.
Evacuation
time
Vacuum
degree
Vacuum
Vacuum
piping
Pipe
coupler
Outlet
(Socket)
Plug
