Refrigerant Length Between Indoor And Outdoor; Air Exhaust - Hitachi air Core 600 Installation & Maintenance Manual

5.3 Refrigerant Length between Indoor and Outdoor

Indoor unit
Height difference H
Max. Pipe
Model
length (L)
18K 25(m)
25K~55K 50(m)
Additional refrigerant charge Q(g):
For 18K: Q=(L-7.5m)×15g/m
For 25K/55K: Q=(L-7.5m)×35g/m

5.4 Air Exhaust

Air and moisture remaining in the refrigerant system
case undesirable effects.
Therefore, they must be removed completely with the
following steps.
(1) Check that each pipe (both narrow and wide pipes
between the indoor and outdoor units) have been
properly connected and all wiring for the test run
has been completed. Note that both narrow and
wide pipe valves on the outdoor unit are kept closed
(2) Using an adjustable wrench or box wrench, remove
the bonnet from the service valve.
(3) Connect a vacuum pump and service valve together
tightly.
(4) Turn on the vacuum pump with the pressure
lower than -0.1MPa (or -1 bar) for 5 minutes.
(5) With the vacuum pump still running, disconnect
pipe of vacuum pump from the service valve. Then
stop the vacuum pump.
(6) Replace the bonnet on the service valve and fasten
it securely with an adjustable wrench or box wrench.
(7) Using an adjustable wrench or box wrench, remove
the bonnet of both narrow and wide valve.
(8) With the hex wrench, turn the wide and narrow pipe
valves stem counter clockwise to fully open the
(9) Replace the bonnets on the wide and narrow valves
and fasten it securely with an adjustable wrench or
box wrench.
Pipe length L
Outdoor unit
Max. Height Add.
difference Refrigerant
(H) (exceed 7.5m)
15(m) 15(g/m)
30(m) 35(g/m)
Installation and Maintenance
Pressure
gauge
Manifold
valve
Vacuum pump
Fig.5.4 Air Purging
CAUTION
An excess or a shortage of refrigerant is the main cause of
trouble to the unit. Charge the correct quantity of refrigerant
according to the description in the manual.
Check refrigerant leakage in detail. If a large refrigerant
leakage occurs, it will cause difficulty in breathing or
harmful gases will occur if a fire is being used in the room.
33
Narrow pipe
Hex wrench
Wide pipe
Bonnet of wide valve
Bonnet of narrow valve
Service valve
Bonnet of service valve
Indoor unit
Outdoor unit