ADDING REFRIGERANT TO THE SYSTEM

TM 5-4120-356-14

4-9.

After completion of system purging and before the system is charged with refrigerant, the system must be

evacuated before new refrigerant is added. Refer to figure 4-4 for evacuation procedures.

After completion of system evacuation in accordance with paragraph 4-9, the unit is ready for

recharging.

NOTE

Whenever available, use recycled refrigerant for charging the refrigeration system.

Connect the refrigerant charging hookup as shown in figure 4-5 with a full cylinder of refrigerant

R-22. Weigh the cylinder so that 4 pounds ( 1.8kg) of refrigerant can be measured into the system.

NOTE

The refrigerant cylinder used for recharging should be equipped with a large capacity

filter drier.

Attach charging line to unit. Do not tighten. Be sure refrigerant cylinder is in an upright position so

only gas will be drawn off.

Open refrigerant cylinder valve slightly and then close to purge air from the charging line. Tighten

charging line on service valve fitting.

Open valve on refrigerant cylinder about 2 turns.

Open the system discharge valve about 2 turns and allow pressure to equalize

Start unit and run until 4 pounds (1.8kg) of refrigerant R-22 is added.

Backseat suction service valve.

Close refrigerant cylinder valve and remove charging line from valve.

Remove manifold and gages (see figure 4-5).

Turn selector switch to the "OFF" position.

ADDING REFRIGERANT TO THE SYSTEM

General. Bubbles or a milky or frothy appearance of the refrigerant passing the sight glass in

normal operation is an indication that the system needs additional refrigerant. The normal refrigerant charge in

the unit when shipped is 4 pounds ( 1.8kg) of R-22 refrigerant. If bubbles or a milky or frothy appearance of the

refrigerant is visible in the sight glass. add refrigerant as follows:

Adding Refrigerant.

Refer to figure 4-5 and install pressure gages with R-22 refrigerant cylinder in an upright

(1)

position.

(2)

Start air conditioner by turning selector switch to the "COOL" position.

Change 4