Air Purging; Air Purging With A Vacuum Pump - Sanyo PNR-XS2432 Installation Instructions Manual

8. 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 tubing
water may lead to corrosion of parts in the refrigerant
system
Air Purging with a Vacuum Pump (for Test Run)
(1) Check that each tube (both narrow and wide tubes)
between the indoor and outdoor units have been
properly connected and all wiring for the test run has
been completed.Note that both narrow and wide tube
service valves on the outdoor unit are kept closed at
this stage.
(2) Using an adjustable wrench or box wrench, remove
the valve caps from the service valve on both narrow
and wide tubes.
(3) Connect a vacuum pump and a manifold valve (with
pressure gauges) to the service port on the wide tube
service valve. (Fig. 8-1)
Be sure to use a manifold valve
for air purging. If it is not
CAUTION
available, use a stop valve for
this purpose. The "Hi" knob of
the manifold valve must always
be kept closed.
(4) With the "Lo" knob of the manifold valve open, run the
vacuum pump. The operation time for the vacuum
pump varies with tubing length and the capacity of the
pump. The following table shows the amount of time
for evacuation:
Required time for evacuation when capacity
of 100 liter/h vacuum pump is used
If tubing length is
less than 33 ft. (10 m)
10 min. or more
NOTE
The required time in the above table is calculated based on
the assumption that the ideal (or target) vacuum condition
is around 10 mmHg abs.
If tubing length is
more than 33 ft. (10 m)
15 min. or more
24
Indoor unit
Outdoor unit
Manifold valve
Pressure
Lo Hi
gauge
Vacuum pump
Fig. 8-1
S4359128
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