6
Air purging
Airtight test
Before starting an airtight test, further tighten the
spindle valves on the gas side and liquid side.
Pressurize the pipe with nitrogen gas charged from the
service port to the design pressure (4.15 Mpa) to
conduct the airtight test.
After the airtight test is completed, evacuate the
nitrogen gas.
Air purge
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.
Do not discharge the refrigerant gas to the
atmosphere to preserve the terrestrial environment.
Use a vacuum pump to discharge the air (nitrogen,
etc.) that remains in the set. If air remains, the
capacity may decrease.
For the vacuum pump, be sure to use one with a
backflow preventer so that the oil in the pump does not
backflow into the pipe of the air conditioner when the
pump stops.
(If oil in the vacuum pump is put in an air conditioner
including R410A, it may cause trouble with the
refrigeration cycle.)
Compound
pressure gauge
Pressure gauge
–101 kPa
Gauge manifold
(–76 cmHg)
valve
Handle Low
Handle High
(Keep fully closed)
Charge hose
Charge hose
(For R410A only)
(For R410A only)
Vacuum pump adapter
for counterflow
prevention
(For R410A only)
Vacuum
pump
Charge port
(Valve core
(Setting pin))
Packed valve at gas side
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1115250101_EN.indd 35
Vacuum pump
As shown in the figure, connect the charge hose after the
manifold valve is closed completely.
Attach the connecting port of the charge hose with a
projection to push the valve core (setting pin) to the charge
port of the set.
Open Handle Low fully.
Turn ON the vacuum pump. (*1)
Loosen the flare nut of the packed valve (Gas side) a little
to check that the air passes through. (*2)
Retighten the flare nut.
Execute vacuuming until the compound pressure gauge
indicates –101 kPa (–76 cmHg). (*1)
Close Handle Low 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.
Open the valve stem or valve handle fully.
(First, at liquid side, then gas side)
Disconnect the charge hose from the charge port.
Tighten the valve and caps of the charge port securely.
*1: Use the vacuum pump, vacuum pump adapter, and gauge
manifold correctly referring to the manuals supplied with each
tool before using them.
Check that the vacuum pump oil is filled up to the specified line
of the oil gauge.
*2: When air is not charged, check again whether the connecting
port of the discharge hose, which has a projection to push the
valve core, is firmly connected to the charge port.
– 35 –
How to open the valve
Open or close the valve.
Liquid side
Open the valve with a 4 mm hexagon wrench.
Gas side
Valve unit
Using a minus
screwdriver, turn it
counterclockwise by
90° until it hits the
stopper. (Full open)
Charge port
Flare nut
Handle position
Groove position
Groove to insert a
screwdriver
Closed completely
Opened fully
While the valve is fully opened, after the screwdriver
has reached the stopper, do not apply torque
exceedin
m. Applying excessive torque may
damage the valve.
Valve handling precautions
Open the valve stem until it strikes the stopper.
It is unnecessary to apply further force.
Securely tighten the cap with a torque wrench.
Cap tightening torque
14 to 18 N m
Ø9.5 mm
(1.4 to 1.8 kgf m)
Valve size
20 to 25 N m
Ø15.9 mm
(2.0 to 2.5 kgf m)
14 to 18 N m
Charge port
(1.4 to 1.8 kgf m)
Replenishing refrigerant
This model is a 30 m chargeless type that does not
need to have its refrigerant replenished for refrigerant
pipes up to 30 m. When a refrigerant pipe longer than
30 m is used, add the specified amount of refrigerant.
Refrigerant replenishing procedure
1. After vacuuming the refrigerant pipe, close the
valves and then charge the refrigerant while the air
conditioner is not working.
2. When the refrigerant cannot be charged to the
specified amount, charge the required amount of
refrigerant from the charge port of the valve on the
gas side during cooling.
Requirement for replenishing refrigerant
Replenish liquid refrigerant.
When gaseous refrigerant is replenished, the
refrigerant composition varies, which disables normal
operation.
Adding additional refrigerant
31~50 m: L
40 g × (L-30)
L: Pipe length
To add an additional amount of refrigerant for twin-
indoor unit types, refer to the installation manual
supplied with the branching pipe (sold separately).
The refrigerant need not be reduced for a 30 meter
(or less) refrigerant pipe.
8/24/13 9:21 AM
8/24/13 9:21 AM
70-EN