– 65 –
Air purge
Undertake the steps described below in each of the
two rooms.
With respect to the preservation of the terrestrial
environment, adopt “Vacuum pump” to purge
air (Evacuate air in the connecting pipes) when
installing the unit.
* Hexagon wrench (4 mm) is required.
1. Connect the charge hose. *1
Check that the handle Hi (manifold valve) is
closed completely.
Attach the connecting port of the charge hose
on the end with a projection to push the valve
core (setting pin) to the service port of the set.
*1 When a control valve or charge valve
is connected between the charge hose
and service port, the R410A refrigerant
can defi nitely be prevented from being
discharged to the atmosphere during the air
purging process.
2. Open Handle Lo fully. Turn ON the vacuum
pump.
Loosen the fl are nut of the connected pipe
(Gas side) a little to check that the air passes
through. Retighten the fl are nut.
If the air fails to enter, check whether the
charge hose is connected securely to the
service port.
Purge the air for 15 or more minutes, and
check that a pressure level of –101 kPa
(–76 cmHg) is indicated on the compound
pressure gauge.
If the compound pressure gauge fails
to indicate a pressure level of –101 kPa
(–76 cmHg), it may mean that air is infi ltrating
from an area where a pipe is connected or
other place. Check the areas where the pipes
are connected.
3. Close Handle Lo completely. Turn OFF the
vacuum pump.
Leave the vacuum pump as it is for 1 or 2
minutes, and check that the indicator of the
compound pressure gauge does not return.
No more refrigerant needs to be added if the
total pipe length is no more than 20 meters.
Add 20 g of refrigerant for every 1 m of piping
that exceeds 21 m.
4. Disconnect the charge hose from the service
port. Open the valve shaft fully with a hexagonal
wrench.
5. Tighten the service port cap and valve stem cap
securely.
Securely tighten these caps with torque in the
following table.
•
•
•
•
•
•
•
•
•
•
6. Check the gas leaks after connection.
Service valve
Tighten torque
Valve stem cap Service port cap
N•m kgf•m N•m kgf•m
Liquid side (6.35) 14 to 18 1.4 to 1.8 — —
Gas side (9.52) 33 to 42 3.3 to 4.2 14 to 18 1.4 to 1.8
Fig. 10-5-9
Compound pressure gauge
–101 kPa (–76 cmHg)
Handle Lo
Charge hose
(For R410A only)
Pressure gauge
Manifold valve
Handle Hi
(Keep full closed)
Charge hose
(For R410A only)
Vacuum pump adapter for
counter-flow prevention
(For R410A only)
Vacuum
pump
Connecting pipe
Service port
(Valve core (Setting pin))
Service valve at gas side
Service valve at liquid side
4mm
Service port cap Valve stem cap
Fig. 10-5-10
Install in rooms that are 5 m³ or larger. If a leak
of refrigerant gas occurs inside the room, an
oxygen defi ciency can occur.
CAUTION
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