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Tightening connection
Align the centers of the connecting pipes and tighten
the flare nut as far as possible with your fingers. Then
tighten the nut with a spanner and torque wrench as
shown in the figure.
CAUTION
• Do not apply excess torque. Otherwise, the nut
may crack depending on the conditions.
(Unit : N•m)
• Tightening torque of flare pipe connections
Pressure of R410A becomes higher than that of R22.
(Approx. 1.6 times) Therefore, using a torque
wrench, tighten firmly 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 a trouble of the refrigeration cycle
or compressor damage.
Half union
Flare nut
Externally
threaded side
Internally
threaded side
Use a wrench to secure.
Use a torque wrench to tighten.
Flare at
indoor unit side
Flare at
outdoor unit side
Outer diam. of copper pipe
6.35 mm (diam.)
9.52 mm (diam.)
12.7 mm (diam.)
15.9 mm (diam.)
Tightening torque
14 to 18 (1.4 to 1.8 kgf•m)
33 to 42 (3.3 to 4.2 kgf•m)
50 to 62 (5.0 to 6.2 kgf•m)
63 to 77 (6.3 to 7.7 kgf•m)
7
EVACUATING
AIR PURGE
Evacuate the air in the connecting pipes and in the
indoor unit using vacuum pump.
Do not use the refrigerant in the outdoor unit.
For details, see the manual of vacuum pump.
Use 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.
1. Connect the charge hose from the manifold valve to
the service port of the gas side packed valve.
2. Connect the charge hose to the port of vacuum
pump.
3. Open fully the low pressure side handle of the
gauge manifold valve.
4. Operate the vacuum pump to start for evacuating.
Perform evacuating for about 35 minutes if the
piping length is total 30 meters for model SM560
and 50 meters for model SM800.
(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 gauge
manifold.
6. Open fully the valve stem of the packed valves
(both sides of Gas and Liquid).
7. Remove the charging hose from the service port.
8. Securely tighten the caps on the packed valves.
6
REFRIGERANT PIPING