Air Purging - Toshiba HWS-P804HR-E Instruction Manual

Air to Water Heat Pump
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 to water heat pump
when the pump stops.
(If oil in the vacuum pump is put in an air to water heat
pump including R410A, it may cause trouble with the
refrigeration cycle.)
Compound pressure gauge
–101 kPa
(–76 cmHg)
Handle Low
Charge hose
(For R410A only)
Charge port
(Valve core (Setting pin))
Packed valve at gas side
Pressure gauge
Gauge manifold valve
Handle High
(Keep fully closed)
Charge hose
(For R410A only)
Vacuum pump
adapter for counter-
flow prevention
(For R410A only)
Vacuum
pump
– 16 –
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.
Installation Manual
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16-EN