Air Purging - Toshiba HWT-801H8W-E Installation Manual

Outdoor Unit
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
Charge port L H
Pressure reducing
Gas leak check
Step 1 ... Pressurize to 0.5 MPa (5 kg/cm
2
Step 2 ... Pressurize to 1.5 MPa (15 kg/cm
Step 3 ... Pressurize to 4.15 MPa (42 kg/cm
Pressurize to 4.6 MPa (46 kg/cm
(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.
23-EN
CAUTION
Never use oxygen, flammable gas, or noxious
gas for the airtight test.
valve
Nitrogen gas
G) for 5 minutes or longer.
Major leaks can be discovered.
G) for 5 minutes or longer.
2
G) <HWT-40, 60 model> for 24 hours.
2
G) <HWT-80, 110, 140 model> for 24 hours.
2
G) per 1°C, so this should be compensated.)
2
■ 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 R32, it may cause trouble with the
refrigeration cycle.)
Micro leaks can be
discovered.
– 12 –
Installation Manual
Compound pressure gauge
Pressure gauge
–101 kPa Gauge manifold valve
(–76 cmHg)
Handle High
Handle Low
(Keep fully closed)
Charge hose Charge hose
(For R32 or (For R32 or R410A only)
R410A only)
Vacuum pump
adapter for backflow
prevention
(For R32 or R410A
only)
Charge port
Vacuum
(Valve core pump
(Setting pin))
Packed valve at gas side
24-EN