Sanyo CH0951 - Manual (Page 18)

18
6. 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 sys-
tem
■ 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 com-
pleted. 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 pres-
sure gauges) to the service port on the wide tube service
valve. (Fig. 52)
(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 evacua-
tion:
Table 6
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.
NOTE
Hi Lo
Indoor unit
Outdoor unit
Manifold valve
Pressure
gauge
Vacuum pump
Fig. 52
Required time for evacuation when capacity
of 100 liter/h vacuum pump is used
If tubing length is If tubing length is
less than 33 ft. (10 m) more than 33 ft. (10 m)
10 min. or more 15 min. or more
CAUTION
Be sure to use a manifold valve for
air purging. If it is not available, use
a stop valve for this purpose. The
“Hi” knob of the manifold valve
must always be kept closed.
01-385 AirCon 12/11/01 4:42 PM Page 18