Fujitsu AS*7A Technical Manual page 138

4. CONNECTION
(1) Install the outdoor unit wall cap (supplied with the
optional installation set or procured at the site) to
the wall pipe.
(2) Connect the outdoor unit and indoor unit piping.
(3) After matching the center of the flare surface and
tightening the nut hand tight, tighten the nut to the
specified tightening torque with a torque wrench.
(Tighten the flare nut of the outdoor unit 3-way
valve after air purging.)
Fig. 24
Tighten with two wrenches.
Flare nut
Torque
wrench
Indoor unit
Connection pipe
pipe
Table 3 Flare nut tightening torque
Flare nut
9.52 mm dia.
15.88 mm dia.
Do not remove the cap from the connection pipe
before connecting the pipe.
5. AIR PURGE
(1) When moving and installing the
room air conditioner, do not mix gas
other than the specified refrigerant
(R22) inside the refrigerant cycle.
(2) Charging of additional refrigerant
(R22) according to the piping length
is unnecessary.
1. VACUUM
(1) Remove the cap, and connect the gauge manifold
and the vacuum pump to the charging valve by the
service hoses.
(2) Vacuum the indoor unit and the connecting pipes
until the pressure in them lowers to below 1.5
mmHg.
(3) Disconnect the service hoses and fit the cap to the
charging valve (Tightening torque : 70 to 90 kgf •
cm).
(4) Remove the blank caps, and fully open the spindles
of the 2-way and 3-way valves with a hexagon
wrench (Torque : 2-way valve: 70 to 90 kgf • cm, 3-
way valve: 100 to 120 kgf • cm).
(5) Tighten the blank caps of the 2-way valve and 3-way
valve to the specified torque (200 to 250 kgf • cm).
Wrench (fixed)
To prevent gas leakage,
coat the flare surface
with refrigerator oil.
Tightening torque
30.4 to 34.3 N • m
(310 to 350 kgf • cm)
73.6 to 78.5 N • m
(750 to 800 kgf • cm)
Fig. 25
Outdoor unit
Service hose
with valve
core
Cap
2. ADDITIONAL CHARGE
Refrigerant suitable for a piping length of 5 m is
charged in the outdoor unit at the factory.
When the piping is longer than 5 m, additional charging
is necessary. For the additional amount, see page 51.
6. GAS LEAKAGE INSPECTION
After connecting the piping, check the
joints for gas leakage with gas leak
detector.
– 137 –
connecting pipe
Blank cap
3-way valve
Charging port
Service hose
Hexagon
wrench
Gauge
manifold
Vacuum
pump