Tubes and Fittings

NOTE: Whenever available, use recycled refigerant for charging the refrigeration system.

CAUTION

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-

the system.

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.

servicing operation.

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

NOTE

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.

before charging.

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.

5-5