(8) Allow vacuum pump to run for one hour after compound gage
reaches 28 inches of mercury.
(9) Shut valves on gage manifold.
(10) Stop vacuum pump and remove hose from the pump.
(11) Connect the hose to a refrigerant R-12 drum.
(12) Open high pressure valve on gage manifold and allow refriger-
ant to enter system on high side.
(13) Close valves after pressure equalizes.
(14) Install common hose on the vacuum pump.
(15) Allow pressure to escape by loosening the hose.
(16) Start the vacuum pump and allow to run until it reaches 28
(17) Repeat steps 11 thru 16 above three times. On final evacua-
tion, let it run for one hour.
(18) Close valves on the gage set and observe for ten minutes. If
vacuum holds, system is ready for charging. If vacuum does not hold,
check for leaks in the refrigerant system.
Whenever available, use recycled refrigerant for charging the refrigera-
d. Charging the System.
(1) Backseat the suction and discharge valves (figure 10).
(2) Install gage set to service valves loosely.
(3) Connect common hose to refrigerant R-12 drum. Open drum
slightly to allow lines to purge. Tighten hose on suction and dis-
(4) Close gage valve on discharge side.
(5) Open service valves from backseat with 1/4 turn (figure 10).
(6) Open refrigerant R-12 drum valve further.
(7) Open gage valve on suction gage side.
(8) Start compressor.
(9) Allow to operate into the system until approximately 44
ounces has entered the unit. Close the refrigerant R-12 drum valves.