.
AIR PURGE
Ev
<Tightening connection>
acuate the air in the connecting pipes and in the
Align the centers of the connecting pipes and tighten
indoor unit using a v
the flare n
acuum pump
ut as f
.
ar as possib
Do not use the
le with y
refr
our fingers
iger
CAUTION
Do not apply excess torque.
Otherwise, the nut may crack depending on the
conditions.
•
•
ant in the outdoor unit.
.
F
or details
Then
, see the
tighten the n
man
ut with a spanner and torque wrench as
ual of the v
sho
acuum pump
wn in the figure
.
.
<Using a v
Fig.
10-4-5
acuum 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 into the air conditioner, which use R410A,
refrigeration cycle trouble may result.)
Flare nut
Half union
Use a wrench to secure.
Use a torque wrench to tighten.
1. Connect the charge hose from the manif
Externally
threaded side
old valv
Internally
threaded side
e to
the service port of the gas side packed valve.
2. Connect the charge hose to the port of the vacuum
pump.
3. Open fully the low pressure side handle of the
gauge manifold valve.
4. Operate the vacuum pump to start evacuating.
Perform evacuating for about 15 minutes if the
piping length is 20 meters. (15 minutes for
20 meters) (assuming a pump capacity of 27 liters
per minute. Then confirm that the compound
pressure gauge reading is -101 kP a (76 cmHg).
5. Close the low pressure side valve handle of gauge
manifold.
6. Open fully the valve stem of the packed valves
(both side of Gas and Liquid).
7. Remove the charging hose from the service port.
8. Securely tighten the caps on the packed valves.
Fig.
10-4-
7
Tightening torque of flare pipe connections
The operating pressure of R410A is higher than that of
R22. (Approx. 1.6 times).
It is therefore necessary to firmly tighten the flare pipe
connecting sections (which connect the indoor and
outdoor units) up to the specified tightening torque.
Incorrect connections may cause not only a gas
leakage, but also damage to the refrigerant cycle.
Fig.
10-4-6
(Unit : N
•
m)
Outer dia.
Tightening torque
of copper pipe
∅
6.35 mm
1
4
to 18 (1.
4
to 1.8 kgf·m)
ˇ 9.52 mm
3
3
to 42 (3.
3
to 4.2 kgf·m)
Flare at
indoor unit side
Flare at
outdoor unit side
∅
Pressure gauge
Manifold valve
–101 kPa (-76 cmHg)
Handle Lo
Connecting pipe
Compound pressure gauge
Vacuum
pump
Handle Hi (Keep full closed)
Charge hose (For R410A only)
Vacuum pump adapter for
counter-flow prevention
(For R410A only)
Packed valve at gas side
Service port (Valve core (Setting pin))
Packed valve at liquid side
Charge hose (For R410A only)
FILE NO. SVM-17030
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