Soap water method

(1)Remove the caps from the 2-way and 3-way valves.

(2)Remove the service-port cap from the 3-way valve.

(3)To open the 2-way valve turn the valve stem coun- terclockwise approximately 90°, wait for about 2~3 sec, and close it.

(4)Apply a soap water or a liquid neutral detergent on the indoor unit connection or outdoor unit connec- tions by a soft brush to check for leakage of the connecting points of the piping.

(5)If bubbles come out, the pipes have leakage.

3.Evacuation

Connect the charge hose end described in the pre- ceding steps to the vacuum pump to evacuate the tub- ing and indoor unit.

Confirm the "Lo" knob of the manifold valve is open. Then, run the vacuum pump.

The operation time for evacuation varies with tubing length and capacity of the pump. The following table shows the time required for evacuation.

Required time for evacuation when 30 gal/h vacuum pump is

used

If tubing length is less than 10m

if tubing length is longer than 10m

(33 ft)

(33 ft)

 

 

10 min. or more

15 min. or more

 

 

When the desired vacuum is reached, close the "Lo" knob of the manifold valve and stop the vacuum pump.

4.Finishing the job

With a service valve wrench, turn the valve stem of liquid side valve counter-clockwise to fully open the valve.

Turn the valve stem of gas side valve counter-clock- wise to fully open the valve.

Loosen the charge hose connected to the gas side service port slightly to release the pressure, then remove the hose.

Replace the flare nut and its bonnet on the gas side service port and fasten the flare nut securely with an adjustable wrench. This process is very important to prevent leakage from the system.

Replace the valve caps at both gas and liquid side service valves and fasten them tight.

This completes air purging with a vacuum pump. The air conditioner is now ready to test run.

-29-

Gas side

Liquid side

3-way valve (Close)

2-way valve (Open)

Cap

Hexagonal wrench

Indoor unit

Outdoor unit

 

Manifold valve

Pressure

Hi

gauge

Lo

 

 

 

Open

Close

Vacuum pump

Page 29
Image 29
LG Electronics LSC183VMA service manual Evacuation, Finishing the job