EVACUATING THE REFRIGERANT SYSTEM. - TM-5-4120-364-130063

TM 5-4120-364-13

(5) Turn selector switch on air conditioner control panel to COOLING.

( 6 ) Observe sight glass while the unit is operating. When frothiness

d i s a p p e a r s , turn suction service valve counterclockwise as far as it will go. Watch

s i g h t glass for approximately 10 minutes to be sure bubbles do not reappear.

(7) Close outlet valve of charging cylinder and backseat the suction

service valve.

( 8 ) Disconnect charging line from suction valve and replace cap.

( 9 ) Return unit to normal operation.

EVACUATING THE REFRIGERANT SYSTEM.

4-9.

a. General. W h e n t h e r e f r i g e r a n t s y s t e i s o p e n e d f o r s e r v i c i n g , t h e r e i s

a possibility of air entering the system. Before closing the system, that portion of

the system which has been opened must be purged of air.

b . Evacuating the low side. When the unit is pumped down to service the lcw

side and there is refrigerant in the receiver, proceed as follows:

( 1 ) Front seat the discharge service valve if it is open. (See figure

4 - 3 ) . Remove plug from the service port of the suction service valve on the comp-

ressor. (See figure 4-2).

(2) Open the r e c e i v e r outlet valve slightly and allow gas to escape

t h r o u g h the suction valve p o r t for a few seconds. R e p l a c e the plug on the service

valve port.

(3) Open the r e c e i v e r o u t l e t v a l v e s l i g h t l y a n d b u i l d pressure to 30

pounds .

( 4 ) Open all v a l v e s f u l l y a n d p l a c e t h e u n i t i n o p e r a t i o n t o i n s p e c t

t h e r e f r i g e r a n t charge.

c. Evacuating t h e h i g h s i d e . When the unit has been pumped down to service

the h i g h s i d e a n d t h e r e i s r e f r i g e r a n t i n t h e r e c e i v e r , p r o c e e d a s f o l l o w s :

( 1 ) Open the discharge service valve (figure 4-3 ), about halfway so the

p o r t is open to the condenser. R e m o v e plug from service valve port.

( 2 ) Open condenser shutoff valve slightly and allow gas to escape for a

f e w seconds. Replace plug on service valve port.

( 3 ) Open receiver outlet valve slightly and build pressure to 30 pounds.

Test for leaks using available leak detector.

( 4 ) Open all refrigerant valves (turn discharge service valve o n e - h a l f

turn clockwise) and place unit in operation to inspect refrigerant charge.

4-7