NOTE: Whenever available, use recycled refigerant for charging the refrigeration system.
e. Charging the System.
If the refrigerant system has been open
( 1 ) Refer to figure 5-1 showing the refrigerant
to the atmosphere for any length of time
charging hookup. Install pressure gages before
due to tube breakage or other reasons,
attempting to charge the system. Open the
replace the dehydrator.
r e f r i g e r a n t drum valve to put a positive pressure in
a. The refrigerant tubes used on the air con-
d i t i o n e r consist of copper tubing and the necessary
(2) Disconnect the vacuum pump from the
fittings. Joints of refrigerant tubes are soldered.
d i s c h a r g e line service valve and connect a suitable
I n s p e c t the tubes and tubing for cracks and breaks.
pressure gage to this valve.
Replace defective tubes with those of the same
( 3 ) Set refrigerant drum in upright position so
l e n g t h , size, shape and material. When removing or
t h a t only gaseous refrigerant will enter system. To
i n s t a l l i n g solenoid valves or expansion valves refer
speed up charging, set refrigerant drum in warm
water. Never use a heating torch for this purpose.
to the applicable paragraph and disassemble the
unit before applying heat in the vicinity of the
(4) Set temperature control switch above
valves. If too much heat is transferred to the in-
ambient or room temperature. Open refrigerant
t e r n a l mechanism of the valves, damage will result.
drum shutoff valve. Operate unit in the cool
b. When a tube or fitting has been soldered into
p o s i t i o n and weigh in 53 oz. charge of refrigerant-
the system it should be checked for leaks and the
22. Continue adding refrigerant slowly until sight
s y s t e m serviced (para 5-8). Always replace holding
glass indicates full.
clamps, insulation and rubber grommets where
(5) Operate unit in cool position only during
t h e y were removed or damaged from excessive heat.
c. F l a r e n u t s s h o u l d b e t i g h t e n e d s e c u r e l y w h e n
(6) Partially block discharge grille with a
cardboard baffle. Adjust baffle until suction
they are being installed on components that were
pressure gage reads 55 PSIG. Continued adding
removed. Flare nuts connections should also be
refrigerant slowly, while maintaining 55 PSIG
checked for leaks.
suction pressure by adjusting the baffle, until the
discharge pressure gage reading corresponds to the
If the refrigerant system has been open to the at-
mosphere for any length of time, due to the tube
ambient temperature. Close refrigerant drum
breakage or component replacement. replace the
shutoff valve. Stop the unit. Disconnect charging
dehydrator. Pressure test and evacuate the system
a n d gage hoses from service valves and install caps.
5-9. Tubes and Fittings
5-10. Analysis of Operation (Electrical System)
a. G e n e r a l . T h e e l e c t r i c a l s y s t e m h e l p s p r o v i d e
Before removing any components from
control for the air conditioning system, drives the
the refrigerant fluid system, the
compressor and circulating fans and provides the
Refrigerant-22 must be discharged.