10-5. EVACUATING
10-5-1. Evacuating
After the piping has been connected to the indoor unit,
you vacuum
both units as once.
Vacuuming
Evacuate the air in the connecting pipes and in the
indoor unit using a vacuum pump. Do not re-use the
refrigerant in the outdoor unit. For details, see the
vacuum pump
manual.
Using a vacuum pump
Be sure to use a vacuum pump with counter-flow
prevention function so that inside oil of the pump does
not flow backward into pipes of the air conditioner
when the pump stops.
(If oil inside of the vacuum pump enters the air
conditioner, which use
s
R410A, refrigeration cycle
trouble may happen.)
1. Connect the charge hose from the manifold valve
to the service port of the packed valve at gas side.
2. Connect the charge hose to the port of the vacuum
pump.
3. Open fully the low pressure side handle of the
manifold valve gauge.
4. Operate the vacuum pump to start evacuating.
Perform evacua
ion
for about 15 minutes if the
piping length is 66 feet (20 m).
(assuming a pump capacity of 27 liters
per minute)
Then confirm that the compound
pressure gauge
reading is -101 kPa (-76 cmHg).
5. Close the low pressure side valve handle of the
manifold valve gauge.
6. Open fully the valve stem of the packed valves
(both gas and liquid sides).
7. Remove the charging hose from the service port.
8. Securely tighten the caps
of
packed valves.
FILE NO. SVM-13069-3
– 6
7
–
Packed valve at
liquid side
Service port (Valve core
(Setting pin))
Packed valve at gas side
Vacuum
pump
Vacuum pump adapter for
counter-flow prevention
(For R410A only)
Charge hose
(For R410A only)
Handle Hi
(Keep full closed)
Manifold valve
Pressure gauge
Compound pressure gauge
Handle Lo
Charge hose
(For R410A only)
Connecting pipe
–101 kPa
(–76 cmHg)
Fig. 10-5-1
.
A
H
Hexagon wrench
is required.
Service Port Cap
Valve Rod Cap
•
5 IMPORTANT POINTS FOR PIPING WORK.
(1) Take away dust and moisture (inside of the
connecting pipes).
(2) Tighten the connections (between pipes and
unit).
(3) Evacuate the air in the connecting pipes using
a VACUUM PUMP.
(4) Check gas leak (connected points).
(5) Be sure to fully open the packed valves before
operation.
•
UNIT DAMAGE HAZARD
Failure to follow this caution may result in
equip
ment damage or improper operation.
Never use the system compressor as a vacuum
pump.
CAUTION
10-5-2. Packed valve handling precautions
•
Open the valve stem all the way out, but do not
try to open it beyond the stopper.
•
Securely tighten the valve cap with torque
in the
following table:
Fig. 10-5-2
Pipe size of Packed Valve Size of Hexagon wrench
1/2 in. (12.7 mm and smallers) A = 3/16 in. (4 mm)
Cap Cap Size (H) Torque
Valve Rod Cap
43/64 in. - 3/4 in.
(H17 - H19)
10 to 13 Ibf.ft
(14~18 N·m)
55/64 in. - 1-3/16 in.
(H22 - H30)
24 to 31 Ibf.ft
(33~42 N·m)
Service Port Cap
35/64 in.
(H14)
37 to 46 Ibf.ft
(50~62 N·m)
43/64 in.
(H17)
10 to 13 Ibf.ft
(14~18 N·m)
