CAUTION
• Do not put the crescent wrench on the cap or cover.
The valve may break.
• If applying excessive torque, the nut may break
according to some installation conditions.
Incorrect
Cover
Cap
• After the installation work, be sure to check for gas
leaks of the pipe connections with nitrogen.
• Therefore, using a torque wrench, tighten the flare
pipe connecting sections that connect the indoor/
outdoor units at the specified tightening torque.
Incomplete connections may cause not only a gas
leak, but also trouble with the refrigeration cycle.
Do not apply refrigerant oil to the flared surface.
123-EN
Branch Pipe
Carry out the refrigerant piping work using the branch
pipe kit which is purchased separately.
Branch pipe installation
The ends of the branch
The ends of the branch
pipes form a line
pipes form a line
perpendicular to the
perpendicular to the
ground.
ground.
Both the collecting pipe
and branch pipes form
Both the collecting pipe
a line parallel to the
and branch pipes form
ground.
a line parallel to the
ground.
Branch pipe
Branch pipe
Collecting pipe
Collection area
Gas side
Liquid side
Inclined
Incorrect
Make sure that the pipes are installed
level after branching.
Length of straight sections on main pipe
side of branch pipe
Provide a straight section with a length of at least
500 mm on the main pipe side of the branch pipe.
(Same for both liquid side and gas side)
500 mm or
more
500 mm or
more
Refrigerant pipe length
Single
\
Allowable pipe length (m)
Outdoor unit
Total length ℓ
Minimum
GM224
5
GM280
5
Pipe diameter (mm)
Outdoor unit
Gas side
GM224
Ø28.6
GM280
Ø28.6
Outdoor Unit
Simultaneous twin
Allowable pipe length (m)
Total length
Branch piping
Outdoor unit
• ℓ1 + ℓ2
• ℓ2
• ℓ1 + ℓ3
• ℓ3
Maximum
Maximum
GM224
60
20
GM280
60
20
Outdoor unit
Main pipe
Gas side
Liquid side
GM224
Ø28.6
GM280
Ø28.6
Outdoor Unit
– 62 –
Height difference (m)
Indoor-outdoor H
Maximum
Indoor unit: Upper
Outdoor unit: Upper
60
30
60
30
Number of bent portions
Liquid side
Ø12.7
10 or less
Ø12.7
10 or less
Figure of Single
Indoor Unit
Height difference (m)
Branch piping
Indoor-outdoor H
• ℓ3 – ℓ2
Indoor unit:
Outdoor unit:
Upper
Upper
Maximum
10
30
30
10
30
30
Pipe diameter (mm)
Branch piping
Gas side
Liquid side
Ø12.7
Ø15.9
Ø9.5
Ø12.7
Ø15.9
Ø9.5
Figure of Simultaneous twin
Indoor Unit
Indoor Unit
2
3
1
30
30
Indoor-indoor
(Δh)
0.5
0.5
Number of bent
portions
10 or less
10 or less
124-EN