Figure 11-1. Pressure Gage Installation and Charging
(10) Operate unit until suction pressure gage
registers between 5 and 10 inches of mercury vacuum.
(11) Shut off machine and observe suction
pressure gage for a few minutes. If pressure rebuilds,
operate unit until pressure does not rebuild appreciably.
(12) Crack receiver outlet valve until three to four
psig is indicated on suction gage.
(13) Close receiver inlet valve by turning valve
stem clockwise as far as it will go.
(14) Remove suction pressure gage.
(15) Before opening the refrigerant system, the
pressure in the system should be known. If the system is
opened under high pressure, excessive loss of refrigerant
will occur. If opened under vacuum, air is drawn into the
system which will cause operating difficulties. If the
pressure gage indicates a vacuum after pumping down,
open the receiver outlet valve slightly to build three to
four pounds of pressure in the system.
(16) Disconnect air conditioner power cord from
right-hand shelter wall adjacent to unit.
(17) Remove the three MS electrical connectors
(see fig. 11-2) on the right side of air conditioner