Air Purging; Air Purge; Vacuum Pump - Toshiba HWS-802H-E Installations-Handbuch

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 terrestrial environment, adopt "Vacuum pump" for air purge
(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.) remained in the set. If the air remains,
the capacity may decrease.
For the vacuum pump, be sure to use one with 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 on the
refrigeration cycle.)

Vacuum pump

As shown in the figure, connect the charge hose after the manifold
valve are 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
the air passes through. (*2)
Tighten the flare nut again.
Execute vacuuming until the compound pressure gauge indicates –
101kPa (–76cmHg). (*1)
Close handle Low completely.
Turn OFF the vacuum pump.
Leave the vacuum pump as it is for 1 or 2 minutes, and check the
indicator of the compound pressure gauge does not return.
Open fully the valve stem or the valve handle. (First, at liquid side,
then gas side)
Outdoor Unit Installation Manual
(continued)
Disconnect the charge hose from the charge port.
Tighten valve and caps of the charge port surely.
* Use the vacuum pump, vacuum pump adapter, and
1
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.
* When air is not charged, check again whether the
2
connecting port of the discharge hose, which has a
projection to push the valve core, is firmly connected
to the charge port.
Compound pressure gauge
–101 kPa
(–76 cmHg)
Handle Lo
Charge hose
(For R410A only)
Charge port
(Valve core
Packed valve
(Setting pin))
at gas side
– 15 –
Pressure gauge
Gauge manifold
valve
Handle Hi
(Keep fully
closed)
Charge hose
(For R410A only)
Vacuum pump
adapter for
counter-flow
prevention
(For R410A only)
Vacuum
pump
14-EN
EN