48
Technical Information
3 REFRIGERATION PIPING WORK
3.1 Refrigeration Piping Work Procedures and Caution in Connecting
3.1.1 Flare Processing
1. Cut the connection pipe with the pipe cutter and remove the burrs.
2. Hold the pipe downward to prevent cuttings from entering the pipe.
3. Remove the flare nuts at the stop valve of the outdoor unit and inside the accessory bag of the indoor unit, then insert
them to the connection pipe, after that, flare the connection pipe with a flaring tool.
4. Check if the flare part is spread evenly and there are no cracks (see Figure 3-3-1).
3.1.2 Bending Pipes
1. The pipes are shaped by your hands. Be careful not to collapse them.
2. Do not bend the pipes in an angle more than 90°.
3. When pipes are repeatedly bent or stretched, the material will harden, making it difficult to bend or stretch them any
more. Do not bend or stretch the pipes more than three times.
4. When bending the pipe, do not bend it as is. The pipe will be collapsed. In this case, cut the heat insulating pipe with a
sharp cutter as shown in Figure 3-3-3, and bend it after exposing the pipe. After bending the pipe as you want, be sure to
put the heat insulating pipe back on the pipe, and secure it with tape.
U-Match Series DC Inverter Service Manual
80
Table 3-2-1
Unit: mm (inch)
Item
Model
A
B
C
D
E
GUHD18ND3FO
955
(37-5/8)
396
(15-5/8)
700
(27-1/2)
560
(22)
360
(14-1/8)
GUHD24ND3FO
980
(38-5/8)
427
(16-3/4)
790
(31-1/8)
610
(24)
395
(15-1/2)
GUHD30ND3FO
GUHD36ND3FO
1107
(43-5/8)
440
(17-3/8)
1100
(43-1/4)
631
(24-7/8)
400
(15-3/4)
GUHD42ND3FO
958
(37-3/4)
412
(16-1/4)
1349
(53-1/8)
572
(22-1/2)
376
(14-3/4)
GUHD48ND3FO
3 REFRIGERATION PIPING WORK
3.1 Refrigeration Piping Work Procedures and Caution in Connecting
3.1.1 Flare Processing
(1) Cut the connection pipe with the pipe cutter and remove the burrs.
(2) Hold the pipe downward to prevent cuttings from entering the pipe.
(3) Remove the flare nuts at the stop valve of the outdoor unit and inside the accessory bag of the
indoor unit, then insert them to the connection pipe, after that, flare the connection pipe with a
flaring tool.
(4) Check if the flare part is spread evenly and there are no cracks (see Figure 3-3-1).
d2
d1
d1
d2
90°±1°
Figure 3-3-1
3.1.2 Bending Pipes
(1) The pipes are shaped by your hands. Be careful not to collapse them.
Extend the pipe by unwinding it
×
Figure 3-3-2
(2) Do not bend the pipes in an angle more than 90°.
(3) When pipes are repeatedly bent or stretched, the material will harden, making it difficult to bend or
U-Match Series DC Inverter Service Manual
80
Table 3-2-1
Unit: mm (inch)
Item
Model
A
B
C
D
E
GUHD18ND3FO
955
(37-5/8)
396
(15-5/8)
700
(27-1/2)
560
(22)
360
(14-1/8)
GUHD24ND3FO
980
(38-5/8)
427
(16-3/4)
790
(31-1/8)
610
(24)
395
(15-1/2)
GUHD30ND3FO
GUHD36ND3FO
1107
(43-5/8)
440
(17-3/8)
1100
(43-1/4)
631
(24-7/8)
400
(15-3/4)
GUHD42ND3FO
958
(37-3/4)
412
(16-1/4)
1349
(53-1/8)
572
(22-1/2)
376
(14-3/4)
GUHD48ND3FO
3 REFRIGERATION PIPING WORK
3.1 Refrigeration Piping Work Procedures and Caution in Connecting
3.1.1 Flare Processing
(1) Cut the connection pipe with the pipe cutter and remove the burrs.
(2) Hold the pipe downward to prevent cuttings from entering the pipe.
(3) Remove the flare nuts at the stop valve of the outdoor unit and inside the accessory bag of the
indoor unit, then insert them to the connection pipe, after that, flare the connection pipe with a
flaring tool.
(4) Check if the flare part is spread evenly and there are no cracks (see Figure 3-3-1).
d2
d1
d1
d2
90°±1°
Figure 3-3-1
3.1.2 Bending Pipes
(1) The pipes are shaped by your hands. Be careful not to collapse them.
Extend the pipe by unwinding it
×
Figure 3-3-2
(2) Do not bend the pipes in an angle more than 90°.
(3) When pipes are repeatedly bent or stretched, the material will harden, making it difficult to bend or
U-Match Series DC Inverter Service Manual
81
stretch them any more. Do not bend or stretch the pipes more than three times.
(4) When bending the pipe, do not bend it as is. The pipe will be collapsed. In this case, cut the heat
insulating pipe with a sharp cutter as shown in Figure 3-3-3, and bend it after exposing the pipe.
After bending the pipe as you want, be sure to put the heat insulating pipe back on the pipe, and
secure it with tape.
Pipe
Cutter
Cutt line
Heat insulating
pipe
Figure 3-3-3
.
To prevent breaking of the pipe, avoid sharp bends. Bend the pipe with a radius of curvature of 150mm (5-7/8inch)
or over.
.
If the pipe is bent repeatedly at the same place, it will break.
3.1.3 Connecting the Pipe at the Indoor Unit Side
Detach the caps and plugs from the pipes.
.
Be sure to apply the pipe against the port on the indoor unit correctly. If the centering is improper, the flare nut
cannot be tightened smoothly. If the flare nut is forced to turn, the threads will be damaged.
.
Do not remove the flare nut until the connection pipe is to be connected so as to prevent dust and impurities from
coming into the pipe system.
When connecting the pipe to the unit or removing it from the unit, please do use both the spanner and
the torque wrench (Figure 3-3-4).
When connecting, smear both inside and outside of the flare nut with refrigeration oil, screw it hand
tight and then tighten it with the spanner.
Refer to Table 3-3-1 to check if the wrench has been tightened properly (too tight would mangle the nut
and lead to leakage).
Examine the connection pipe to see if it leaks, then take the treatment of heat insulation, as shown in
the Figure 3-3-4.
Use the medium-sized sponge to insulate the coupler of the gas pipe.
CAUTION!
To prevent breaking of the pipe, avoid sharp bends. Bend the pipe with a radius of curvature of 150mm (5-7/8inch) or over.
If the pipe is bent repeatedly at the same place, it will break.
