FILE NO. SVM-12053
CAUTION
• Do not apply excess torque. Otherwise, the
nut may crack depending on the conditions.
(Unit : N·m)
10-4-3. Evacuating
After the piping has been connected to the indoor
unit, you can perform vacuuming together at once.
<Vacuuming>
Evacuate the air in the connecting pipes and in
the indoor unit using a vacuum pump.
Do not use the refrigerant in the outdoor unit.
For detail
s, see the vacuum pump.
Outer dia. of copper pipe
Ø6.35 mm
Ø12.7 mm
Tightening torque
14 to 18 (1.4 to 1.8 kgf•m)
50 to 62 (5.0 to 6.2 kgf•m)
<Tightening orque of flare pipe connections>
The operating oressure 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
refrigeration cycle.
Fig. 10-4-5
Flare at indoor unit side
Flare at outdoor unit side
<Use a vacuum pump>
Be sure to use a vacuum pump with counter-flow
prevention function so that oil inside 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
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
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 kPa (–76 cmHg).
5. Close the low pressure valve handle of gauge
manifold valve.
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 on the packed valves.
conditioner, which use R410A, refrigeration cycle
trouble may happen.
Packed valve at liquid side
Service port (Valve core (Setting pin))
Packed valve at gas side
Vacuum pump adapter for
counter-Low prevention
(For R410A only)
Charge hose
(For R410A only)
Handle Hi
(Keep full closed)
Manifold valve
Compound pressure gauge Pressure gauge
Handle Lo
Charge hose
(For R410A only)
Connecting pipe
–101 kPa
(–76 cmHg)
Vacuum
pump
Fig. 10-4-6
– 54 –
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