TM 9-4120-407-14
(12) Set refrigerant cylinder to deliver gas only.
Never introduce high discharge pressure into a refrigerant cylinder.
This can cause the cylinder to rupture and injure personnel.
(13) Check that pressure gauge valve is closed.
(14) Open compound gauge and charge valves.
(15) Continue to charge until sight glass remains clear and bubble-free for 15 minutes.
(16) Close compound gauge, charge, and refrigerant cylinder valves.
(17) Turn rotary MODE selector switch to OFF RESET.
NOTE
FOLLOW-ON MAINTENANCE:
Remove service manifold. See para 4-11.
4-19. REFRIGERANT SYSTEM PRESSURE CHECK.
This task covers:
Testing
Equipment Conditions:
Tools
Service manifold installed. See para 411.
Refrigeration Unit Service Tool Kit
(Item 1, Appendix B)
Goggles (Item 1, Appendix B)
Gloves (Item 2, Appendix B)
Testing
(1) Check that all four service manifold valves are closed and Air Conditioner discharge and suction
service valves are open.
(2)
Both gauges should read the same. Check the reading with the appropriate column in Table 4-2.
If the system is even partially charged, the pressure should be approximately equal to that
shown in the table for the appropriate ambient temperature. If the pressure is considerably less
than shown in the table, the system does not contain enough refrigerant to continue the pressure
check. See paragraph 4-16 for leak testing.
(3) Turn air conditioner on and operate in COOL mode with potentiometer TEMPERATURE control set
at maximum COOL position for five minutes.
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