Specifications
AES
97
Fig. 8-1
Fig. 8-2
Fig. 8-3
8. AIR PURGING
Air and moisture in the refrigerant system may have
undesirable effects as indicated below.
● pressure in the system rises
● operating current rises
● cooling (or heating) efficiency drops
● moisture in the refrigerant circuit may freeze and
block capillary tubing
● water may lead to corrosion of parts in the refriger-
ant system
Therefore, the indoor unit and tubing between the
indoor and outdoor unit must be leak tested and
evacuated to remove any noncondensables and
moisture from the system.
■ Air Purging with a Vacuum Pump (for Test Run)
Preparation
Check that each tube (both narrow and wide tubes)
between the indoor and outdoor units has been prop-
erly connected and all wiring for the test run has been
completed. Remove the valve caps from both the
wide and narrow service valves on the outdoor unit.
Note that both narrow and wide tube service valves
on the outdoor unit are kept closed at this stage.
Leak test
(1) With the service valves on the outdoor unit closed,
remove the 1/4 in. flare nut and its bonnet on the
wide tube service valve. (Save for reuse.)
(2) Attach a manifold valve (with pressure gauges)
and dry nitrogen gas cylinder to this service port
with charge hoses.
(3) Pressurize the system to no more than 38 kgf/cm
2
G
with dry nitrogen gas and close the cylinder valve
when the gauge reading reaches 38 kgf/cm
2
G.
Then, test for leaks with liquid soap.
Manifold gauge
Outlet
Inlet
Vacuum pump
Manifold valve
Pressure
gauge
Lo Hi
Charge hose
Outdoor unit
Close
Open
Narrow
tube
Wide
tube
Balance
tube
Nitrogen gas cylinder
(In vertical standing
position)
Close
Open
Close
Open
Cylinder
valve
Use a manifold valve for air
purging. If it is not available,
use a stop valve for this pur-
pose. The “Hi” knob of the
manifold valve must always
be kept closed.
CAUTION
CAUTION
To avoid nitrogen entering
the refrigerant system in a
liquid state, the top of the
cylinder must be higher than
the bottom when you pres-
surize the system. Usually,
the cylinder is used in a ver-
tical standing position.
(Refer to the previous page.)
04-396 InverterW_p51-108 ARGO 12/21/04 10:17 AM Page 97