Air Purging - Toshiba RAV-SP404ATP-E Installation Manual

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. Perform gas leak checks using
a leak tester for the HFC refrigerant.
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 counter-
flow prevention
(For R410A only)
Vacuum
pump
Packed valve at gas side
Charge port
(Valve core
(Setting pin))
EN-23
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.
How to open the valve
Open or close the valve.
Liquid side, gas side
Open the valve with a 4 mm hexagon wrench.
[Hexagonal wrench is required.]
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
Valve size Ø6.4 mm 14 to 18 N•m
(1.4 to 1.8 kgf•m)
Ø12.7 mm 33 to 42 N•m
(3.3 to 4.2 kgf•m)
Charge port 14 to 18 N•m
(1.4 to 1.8 kgf•m)
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Replenishing refrigerant
This model is a 20 m chargeless type that does not need
to have its refrigerant replenished for refrigerant pipes up
to 20 m. When a refrigerant pipe longer than 20 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
SP40, 45 SP56
21~30 m: L 21~50 m: L
20 g × (L-20) 20 g × (L-20)
• L: Pipe length
• The refrigerant need not be reduced for a 20 meter (or
less) refrigerant pipe.
EN-24