LG Electronics LP121CEM-Y8 manual LGE Internal Use Only

NOTES

—Replacement of the refrigeration cycle.

1.When replacing the refrigeration cycle, be sure to discharge the refrigerant system using a refrigerant recovery system.

If there is no valve to attach the recovery system, install one (such as a WATCO A-1) before venting the refrigerant. Leave the valve in place after servicing the system.

2.After discharging the unit completely, remove the desired component, and unbraze the pinch-off tubes.

3.Solder service valves into the pinch-off tube ports, leaving the valves open.

4.Solder the pinch-off tubes with service valves.

5.Evacuate as follows.

1)Connect the vacuum pump, as illustrated Figure 21 A.

2)Start the vacuum pump, slowly open manifold valves A and B with two full turns counterclockwise and leave the valves closed. The vacuum pump is now pulling through valves A and B up to valve C by means of the manifold and entire system.

CAUTION

If high vacuum equipment is used, just crack valves A and B for a few minutes, then open slowly with the two full turns counterclockwise. This will keep oil from foaming and being drawn into the vacuum pump.

3)Operate the vacuum pump for 20 to 30 minutes, until 600 microns of vacuum are obtained. Close valves A and B, and observe the vacuum gauge for a few minutes. A rise in pressure would indicate a possible leak or moisture remaining in the system. With valves A and B closed, stop the vacuum pump.

4)Remove the hose from the vacuum pump and place it on the charging cylinder. See Figure 21 B. Open valve C.

Discharge the line at the manifold connection.

5)The system is now ready for final charging.

6.Recharge as follows :

1)Refrigeration cycle systems are charged from the high-side. If the total charge cannot be put

in the high-side, the balance will be put in the suction line through the access valve which you installed as the system was opened.

2)Connect the charging cylinder as shown in Figure 21 B.

With valve C open, discharge the hose at the manifold connection.

3)Open valve A and allow the proper charge to enter the system. Valve B is still closed.

4)If more charge is required, the high-side will not take it. Close valve A.

5)With the unit running, open valve B and add the balance of the charge.

a.Do not add the liquid refrigerant to the low- side.

b.Watch the low-side gauge; allow pressure to rise to 30 lbs.

c.Turn off valve B and allow pressure to drop.

d.Repeat steps B and C until the balance of the charge is in the system.

6)When satisfied the unit is operating correctly, use the pinch-off tool with the unit still running and clamp on to the pinch-off tube. Using a tube cutter, cut the pinch-off tube about 2 inches from the pinch-off tool. Use sil-fos solder and solder pinch-off tube closed. Turn off the unit, allow it to set for a while, and then test the leakage of the pinch-off connection.

Copyright ©2008 LG Electronics. Inc. All right reserved.	- 15 -
Only for training and service purposes	LGE Internal Use Only