Hitachi RAS-2HVNP Installations- Und Betriebshandbuch Seite 25

14
1 Refrigerant piping & refrigerant charge
Hexagonal wrench size used for spindle valve:
(*) Size
2HP, 2.5HP
Gas valve
Liquid valve
Do not apply two spanners
at this position. If applied,
leakage will occur.
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 specification
14.3.2 Piping system for header branch
1 indoor unit system
2 indoor units system
(pictures are as example)
25
PMML0248A
3HP
4 mm 5 mm
4 mm 4 mm
Stop valve
(Spindle type)
Flare nut
C A U T I O N
• 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 difficulty with breathing or har-
mful gases would occur if a fire was being used in the room.

Maximum refrigerant piping length
Outdoor Unit
Maximum piping Actual Length (L)
length between the
Equivalent Length
outdoor unit and the
(EL)
farthest indoor unit
Total piping length 2 units (A+B+C)
Maximum piping line
2 units (B, C)
after first branch
Main piping length A
Maximum height difference
Outdoor / Indoor (H)
(Outdoor Unit is Higher / Lower.)
Maximum height difference Indoor / Indoor
Maximum height difference:
branch pipe/Indoor (2 indoor units system)
(B-C)
N O T E
• 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.
(m)
IVX ES
2HP 2.5HP 3HP 3HP
50
70
50 60
10
A > B, C
30 / 20
3 10 0.5
3 0.5
< 8