Installation and operation manual
16
10T8Y1B
VRV-W IV System Air Conditioner
4P399208-1 – 2015.01
Precautions when connecting pipes
See the following table for flare part machining dimensions.
When connecting the flare nuts, apply refrigerant oil to the inside
and outside of the flares and screw them in by hand three or four
times at first.
(Use ester oil or ether oil.)
See the following table for tightening torque.
(Applying too much torque may cause the flares to crack.)
After all the piping has been connected, check the gas leak with
nitrogen.
10.2.2
Connect piping to outdoor unit by using accessory
pipes
A
Heat pump system (2-pipe)
B
Heat recovery system (3-pipe)
1
Gas side piping (field supply)
2
Accessory pipe
3
Liquid side pipe (field supply)
4
Flare nut (Included in the unit)
5
Accessory pipe is not used. Blind flange remains on
suction pipe.
6
Piping on HP/LP gas side (field supply)
7
Piping on suction gas side (field supply)
8
Cut off the hatched area and use it as a cover.
9
Hatched area
10
Accessory pipe
11
Guideline for pipe machining
12
Accessory pipe
13
Brazing
14
Accessory pipe
15
Before fitting to the product, apply brazing.
10.2.3
Branching the refrigerant piping
For installation of the refrigerant branching kit, refer to the
installation manual delivered with the kit.
1
Horizontal surface
1
Mount the Refnet joint so that it branches either horizontally
or vertically.
2
Mount the Refnet header so that it branches horizontally.
Installation of the multi outdoor unit connection piping kit.
Pipe size
Tightening
torque (N·m)
A (mm)
Flare shape
Ø9.5
32.7~39.9
12.8~13.2
Ø12.7
49.5~60.3
16.2~16.6
Ø15.9
61.8~75.4
19.3~19.7
NOTICE
Not recommended but in case of emergency
You must use a torque wrench but if you are obliged to
install the unit without a torque wrench, you may follow the
installation method mentioned below.
After the work is finished, make sure to check that
there is no gas leak.
When you keep on tightening the flare nut with a spanner,
there is a point where the tightening torque suddenly
increases. From that position, further tighten the flare nut
with the angle shown below:
When loosening a flare nut, always use two wrenches
in combination. When connecting the piping, always
use a spanner and torque wrench in combination to
tighten the flare nut.
When connecting a flare nut, coat the flare (inner and
outer faces) with ether oil or ester oil and hand-tighten
the nut 3 to 4 turns as the initial tightening.
R=0.4~0.8
45°±2
90°±2
A
Pipe size
Further tightening
angle
Recommended arm
length of tool
Ø9.5
60~90°
±200 mm
Ø12.7
30~60°
±250 mm
Ø15.9
30~90°
±300 mm
A
B
1
2
3
4
*5
6
7
8
9
10
4
3
10
12
13
14
*15
[11]
A
B
±3
0
°
1
1
A
1
max
15
B
1
>120 mm
>500 mm
