Air Purging - Toshiba RAV-GE6001A8P-T Installation Manual

6

Air purging

Airtight Test
■
After completing the refrigerant piping work, perform an airtight test. Connect a nitrogen gas cylinder and
pressurize the pipes with nitrogen gas as follows to conduct the airtight test.
Low pressure gauge High pressure gauge
Gauge manifold
V V
L H
Charge port
Pressure reducing
valve
Gas leak check
Step 1....Pressurize to 0.5 MPa (5 kg/cm G) for 5 minutes or longer.
2
Step 2....Pressurize to 1.5 MPa (15 kg/cm G) for 5 minutes or longer.
2
Step 3....Pressurize to 4.50 MPa (45 kg/cm 2 G) for 24 hours. ................ Micro leaks can be discovered.
(However, note that when the ambient temperature differs during pressurization and after 24 hours, the pressure
will change by approximately 0.01 MPa (0.1 kg/cm
If the pressure drops in steps 1 through 3, check the connections for leakage.
Check for leaks with foaming liquid, etc., take steps to fix the leaks such as brazing the pipes again and
tightening the flare nuts, and then perform the airtight test again.
* After the airtight test is completed, evacuate the nitrogen gas.
27-EN
1121901101.indd 15
CAUTION
Never use oxygen, flammable gas,
or noxious gas for the airtight test.
Nitrogen gas
Major leaks can be discovered.
2 G) per 1°C, so this should be compensated.)
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 R32, 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 R32/R410A)
(For R32/R410A)
Vacuum pump adapter
for counterflow
prevention
(For R32/R410A)
Vacuum
pump
Charge port
(Valve core
(Setting pin))
Packed valve at gas side
– 14 –
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.
28-EN
10/1/2562 11:10:12
EN