Hisense kf-34gwe User Guide

5.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 efficiency drops
·moisture in the air may freeze and block capillary tubing
·water may lead to corrosion of parts in the refrigerant system
5-1.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.A)

(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

CAUTION

Be su r e t o us e a m a n i f o l d v alve fo r a ir pu r g i ng.
I f i t i s not ava i l a b l e , use a s t o p v alve for
this p u r p ose. T h e “ H i” k n o b of t h e manif o l d
valve mu s t a lwa y s b e kep t c losed.

Indoor unit

Outdoor unit

Fig.A

Manifold valve

Pressure

gauge

Vacuum pump

Table

Required time for evacuation when capacity

of 100 liter/h vacuum pump is used

If tubing length is less than 10 m

10 min. or more

15 min. or more

If tubing length is more than 10 m

Appendix: Installation

90 (1/4 turn)

Narrow tube

Hex wrench

Wide tube

Valve cap

Vacuum hose to manifold valve

Fig.B

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.

(5) With the vacuum pump still running, close the “Lo”knob of the

manifold valve. Then stop the vacuum pump.

(6)With the accessory hex wrench, turn the valve stem on the narrow

tube service valve counterclockwise by 90 degrees (1/4 turn) for
10 seconds, and then turn the stem clockwise to close it again.

(Fig.B)

NOTE

CAUTION

Be sure to completely insert the hex wrench
before attempting to turn the valve.