Panasonic CS-Z25UB4EAW Service Manual page 47

12.2.3 Connect the Piping
12.2.3.1 Connecting the Piping to Indoor
For connection joint location at outside building
Please make flare after inserting flare nut (locate at
joint portion of tube assembly) onto the copper pipe.
(In case of using long piping)
Connect the piping

Align the center of piping and sufficiently tighten
the flare nut with fingers.

Further tighten the flare nut with torque wrench in
specified torque as stated in the table.
Spanner
or Wrench
12.2.3.2 Connecting the Piping to Outdoor
Decide piping length and then cut by using pipe cutter.
Remove burrs from cut edge. Make flare after
inserting the flare nut (locate at valve) onto the copper
pipe. Align center of piping to valve and then tighten
with torque wrench to the specified torque as stated in
the table.
12.2.4 Evacuation of the Equipment
WHEN INSTALLING AN AIR CONDITIONER, BE SURE TO EVACUATE THE AIR INSIDE THE INDOOR UNIT AND
PIPES in the following procedure.
1 Connect a charging hose with a push pin to the Low side of a charging set and the service port of the 3-way
valve.
Be sure to connect the end of the charging hose with the push pin to the service port.
o
2 Connect the center hose of the charging set to a vacuum pump.
3 Turn on the power switch of the vacuum pump and make sure that the needle in the gauge moves from
0 cmHg (0 MPa) to -76 cmHg (-0.1 MPa). Then evacuate the air approximately ten minutes.
4 Close the Low side valve of the charging set and turn off the vacuum pump. Make sure that the needle in the
gauge does not move after approximately five minutes.
Note : BE SURE TO TAKE THIS PROCEDURE IN ORDER TO AVOID REFRIGERANT GAS LEAKAGE.
5 Disconnect the charging hose from the vacuum pump and from the service port of the 3-way valve.
6 Tighten the service port caps of the 3-way valve at a torque of 18 N•m with a torque wrench.
Torque wrench
Indoor unit
Lo
Vacuum
pump
For connection joint location at inside building

Refer to indoor installation instruction.
Do not overtighten, overtightening may cause gas leakage
Liquid side
Two-way valve
Closed
Gas side
Three-way valve
Closed
Hi
CLOSE
OPEN
47
Piping size
6.35 mm (1/4")
9.52 mm (3/8")
12.7 mm (1/2")
15.88 mm (5/8")
19.05 mm (3/4") [100 N•m (10.2 kgf•m)]
Outdoor unit
Torque
[18 N•m (1.8 kgf•m)]
[42 N•m (4.3 kgf•m)]
[55 N•m (5.6 kgf•m)]
[65 N•m (6.6 kgf•m)]