Air Purging - Sanyo COOL Installation Instructions Manual

9. Air Purging

Air and moisture remaining in the refrigerant system
have undesirable effects as indicated below. Therefore,
they must be purged completely.
pressure in the system rises
operating current rises
cooling (or heating) efficiency drops
moisture in the air may freeze and block capillary tub-
ing
water may lead to corrosion of parts in the refrigerant
system
Air Purging with a Vacuum Pump (for Test Run)
Check that each tube (both narrow and wide tubes)
between the indoor and outdoor units have been proper-
ly 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". flare nut and its bonnet on the wide
tube service valve. (Save them for reuse.)
(2) Attach a manifold valve (with pressure gauges) and
dry nitrogen gas cylinder to this service port with
charge hoses.
Use a manifold valve for air
CAUTION
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.
(3) Pressurize the system to no more than 150 P.S.I.G.
with dry nitrogen gas and close the cylinder valve
when the gauge reading reaches 150 P.S.I.G. Then,
test for leaks with liquid soap.
Manifold valve
Pressure
Lo
gauge
Narrow
tube
Pressure
gauge
Cap
Narrow tube
Wide tube
22
Hi
Charge hose
Nitrogen gas cylinder
(In vertical standing
position)
Outdoor unit
Service
valve
Wide tube
Indoor unit
Fig. 46
Manifold valve
Lo Hi
Nitrogen gas
cylinder
Fig. 47