Figure 5-1. Refrigerant charging hook up.

(9) Test system for leaks (para 5-8a).

the access cover at the back of the unit. Remove the

(10) If no leaks are detected, disconnect the

access cover.

p r e s s u r e testing hookup. Connect a suitable hose to

(2) Refer to figure 5-1 and make up a

the discharge line service valve to allow test gases to

charging hookup as shown.

escape.

(3) Remove cap from suction line service

(11) Remove cap from discharge line service

valve and connect the charging hookup to the

v a l v e . Attach a suitable vacuum pump to discharge

service valve.

l i n e service valve and a manometer to suction line

(4) Open shutoff valve to full open.

s e r v i c e valve. With the service valves open, operate

NOTE

vacuum pump until manometer indicates 2.5 mm

Refrigerant drum must be in upright position to allow

(millimeters).

only gaseous refrigerant to enter system.

(12) Close valve at vacuum pump and stop

refrigerant, u n t i l s y s t e m p r e s s u r e

(5)

Add

pump. Allow unit to stand under vacuum for one

g a g e reads 50 PSIG (Pounds per square inch gage)

hour. If no noticeable rise in pressure occurs, the

minimum. Close the drum shutoff valve.

system is

ready for charging. Disconnect

(6) Disconnect charging hookup and connect

manometer from suction line service valve and

t h e pressure testing hookup (fig. 5-2) to the suction

connect the refrigerant charging hookup to this

line service valve.

valve. Operate vacuum pump for another thirty

(7) Open the shutoff valve to full open.

(30) minutes. Close vacuum pump valve and stop

(8) Add nitrogen and adjust pressure

pump.

regulator

until

drum

pressure

gage

reads

150

PSIG. Close the drum shutoff valve.

Figure 5-1. Refrigerant charging hook up.

5-4