14.3.2 Piping system for header branch
1 indoor unit system
2 indoor units system
(pictures are as example)
Maximum refrigerant piping length
(m)
Outdoor Unit
IVX ES
2HP 2.5HP 3HP 3HP
Maximum piping
length between the
outdoor unit and the
farthest indoor unit
Actual Length (L)
50
Equivalent Length
(EL)
70
Total piping length 2 units (A+B+C)
50 60
Maximum piping line
after rst branch
2 units (B, C)
10
Main piping length A
A > B, C
Maximum height difference
Outdoor / Indoor (H)
(Outdoor Unit is Higher / Lower.)
30 / 20
Maximum height difference Indoor / Indoor
3 3 0.5
Maximum height difference:
branch pipe/Indoor (2 indoor units system)
3 0.5
(B-C)
< 8
NOTE
• The liquid piping and the gas piping must be of the same
piping length and run along the same route.
• Install the branch piping as much as possible near the indoor
units
• Install Multikits at the same horizontal level.
14
Hexagonal wrench size used for spindle valve:
(*) Size
2HP, 2.5HP 3HP
Gas valve 4 mm 5 mm
Liquid valve 4 mm 4 mm
Do not apply two spanners
at this position. If applied,
leakage will occur.
Stop valve
(Spindle type)
Flare nut
CAUTION
• At the test run, fully open the spindle and ball stop valve.
• If not fully opened, the devices will be damaged.
• Do not attempt to turn service valve rod beyond its stop.
• Do not loosen the stop ring. If the stop ring is loosened, it is
dangerous since the spindle will hop out.
• An excess or a shortage of refrigerant is the main cause of
trouble to the units. Charge the correct refrigerant quantity
according to the description of label at the inside of service
cover.
• Check for refrigerant leakage in detail. If a large refrigerant
leakage occurs, it will cause difculty with breathing or har-
mful gases would occur if a re was being used in the room.
14.3 REFRIGERANT PIPING LENGTH
The refrigerant piping between the indoor unit and the outdoor unit should be designed using the beside chart.
Keep the design point within the dark area of the chart, which is showing the applicable height difference according to piping length.
In case that a piping length is shorter than 5 meters, contact the Hitachi dealer.
14.3.1 Piping Length specication
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