Figure 6-1. Pressure testing and evacuating the refrigerant system.

Figure 6-1. Pressure testing and evacuating the refrigerant system.

Attach hose from refrigerant drum, purge air

(11) Close suction service valve and allow

from line with refrigerant and slowly break the

unit to stand under vacuum for approximately 12

vacuum by opening the suction service valve until

hours. If no noticeable rise in pressure occurs, the

760 mm hg. abs. Close suction service valve.

system is ready for changing. Close service

valves, remove vacuum pump, manometer and

(10) Remove refrigerant drum and attach

vacuum pump to the suction service valve. Purge

install valve caps.

air from hose, start pump and open suction ser-

Note. Rise in pressure will be influenced by am-

vice valve. Operate pump until manometer again

bient temperature. Make sure that vacuum in system is

indicates 2.5 mm hg. abs.

completely relieved before charging.

6-2