Use and Care Manual

Fig.4.16

Trap

If the outdoor unit is installed higher than

the indoor unit (See Fig.4.16)

(1). If taping, it must be done from lower to

the upper part.

(2). All pipes are bound together with

cable clamps. The drain hose must contain

a trap to prevent water from

returning to the indoor unit.

(3). Restraint all pipes to the wall with

attaching clamp.

4.4 Vacuum and Gas Leakage Inspection

Alway use a vacuum pump, rather than refrigerant, to discharge air when installing the unit.

4.4.1 Vacuum

(1). Remove the caps of the liquid valve, gas valve and also the service port.

(2). Connect the hose at the low pressure side of the manifold valve assembly to the service

port of the unit’s gas valve, and meanwhile the gas and liquid valves should be kept closed

in case of refrigerant leak.

(3). Connect the hose used for evacuation to the vacuum pump.

(4). Open the switch at the lower pressure side of the manifold valve assembly and start the

vacuum pump. Meanwhile, the switch at the high pressure side of the manifold valve

assembly should be kept closed, otherwise evacuation would fail.

(5). The evacuation duration depends on the unit’s capacity, generally, 20 minutes for the 18K

units, 30 minutes for the 24/30/36K units, 45 minutes for the 42/48K units. And verify if

the pressure gauge at the low pressure side of the manifold valve assembly reads -1.0Mp

(145psig), if not, it indicates there is leak somewhere. Then, close the switch fully and then

stop the vacuum pump.

(6). Wait for some time to see if the system pressure can remain unchanged, 5 minutes for the

18/24/30K units, 10 minutes for the units 36/42/48K. During this time, the reading of the

pressure gauge at the low pressure side can not be larger 0.005Mpa (0.72psig)..

(7). Slightly open the liquid valve and let some refrigerant go to the connection pipe to balance

the pressure inside and outside of the connection pipe, so that air will not come into the

connection pipe when removing the hose. Note that the gas and liquid valve can be opened

fully only after the manifold valve assembly is removed.

(8). Place back the caps of the liquid valve, gas valve and also the service port.

U-match Series Cassette Type Unit