Protection Of Pipes; Pipe Installation; Brazing; Indoor Unit Pipe Connections - Fujitsu AJ*A72LALH Series Installation Manual

4. 3.

Protection of pipes

Location
Outdoor
Indoor
5.

PIPE INSTALLATION

5. 1.

Brazing

• If air or another type of refrigerant enters the refrigeration cycle, the
internal pressure in the refrigeration cycle will become abnormally
high and prevent the unit from exerting its full performance.
• Apply nitrogen gas while brazing the pipes.
Nitrogen gas pressure: 0.02 MPa (= pressure felt suffi ciently on the
back of your hand)
• If a pipe is brazed without applying nitrogen gas, it will create an oxidation fi lm.
This can degrade performance or damage the parts in the unit (such as the compressor or valves).
• Do not use fl ux to braze pipes. If the fl ux is the chlorine type, it will cause the pipes to corrode.
In addition, if the fl ux contains fl uoride, it will affect the refrigerant piping system due to deterioration of refrigerant oil.
• For brazing material, use phosphor copper that does not require fl ux.
5. 2.

Indoor unit pipe connections

Separation tube
Horizontal
A
±15°C
OK
A : Outdoor unit or Refrigerant branch kit
B : Indoor unit or Refrigerant branch kit
Header
Gas pipe
C
Outdoor
unit side
Liquid pipe
D
Outdoor
unit side
OK
Working period Protection method
1 month or more
Less than 1 month Pinch or tape pipes
— Pinch or tape pipes
B
A
Vertical
or
Horizontal line
B
Horizontal
line 1
Horizontal
line
1
H
1
VIEW C
Horizontal
Horizontal
line
line
2
H
2
2
VIEW D
• Protect the pipes to prevent the entry of mois-
ture and dust.
Pinch pipes
• Especially pay attention when passing the pipes
through a hole or connecting the end of a pipe
to the outdoor unit.
CAUTION
Fig.
CAUTION
B
A
H = 0 mm –
1
10 mm
( : 0 – 1 )
1
: -10 – 10
1
H = 0 mm –
2
10 mm
( : 0 – 1 )
2
: -10 – 10
2
NO GOOD
Pressure regulating valve
Cap
Nitrogen gas
Brazing area
NO GOOD
NO GOOD
En-13