Casing Assembly - TM-5-4120-285-150093

Figure 515--Continued.

5-26. Suction and Discharge Service Valves

the system. Leaving a permanent type filter-dryer

in the suction line allows the serviceman to com-

a. General. The suction and discharge service

plete the clean-up at one time, A pressure tap

valves provide access to the refrigerant system.

should be installed upstream of the suction filter-

b. Removal.

dryer so that the pressure drop from the tap to

(1) Remove the condenser fan (para 3-19).

the service valve can be checked after several

(2) Discharge the refrigerant system (para

hours of operation. A pressure drop in excess of 3

6-1).

psi is generally considered excessive.

(3) Refer to figure 5-16 and remove the ser-

(3) Check the expansion device and clean or

vice valves as follows: Both valves must be

replace it. Replace sight glass.

sweated from the lines. Apply heat carefully to

(4) Remove the burned out compressor and

avoid damage to adjacent components.

install the replacement.

c. Installation.

(5) Evacuate the system.

(1) Install the service valves by reversing

(6) Recharge the system and put in opera-

the order of removal.

tion.

(2) Replace the dehydrator (para 5-18).

(7) Check pressure drop across suction fil-

(3) Evacuate and recharge the refrigerant

ter-dryer after one hour operation. Change if nec-

system (para 61 ).

essary and evacuate system.

(8) After 8--24 hours operation, change

suction filter-dryer, check odor and color of oil or

test with test kit. Evacuate system.

(9) After 14 days of operation, check color

and acidity of oil. If required, change filter-

dryers. Before clean-up is complete, it is essential

that oil is clean and no acid is present.

Note. The new compressor should not be used for

pulling a vacuum. Pull a high vacuum (less than 500 mi-

crons) for several hours. Allow the system to stand sev-

eral hours to be sure the vacuum is maintained.

5-25. Casing Assembly

a. General. The casing assembly protects and

provides air control around the components. Re-

moval and installation instructions for the access

panels, covers, grills, and screens have been in-

cluded in the applicable component maintenance

instructions. Figure 515 is provided as a guide

should it become necessary to remove panels or

insulation not previously covered.

b. Removal. Refer to figure 515 and remove

casing components as required.

Note. The majority of the panels have been installed

with rivet nuts and must be removed carefully so as to

avoid damage to the equipment.

c. Installation. Install the casing components

Figure 51 6. Discharge and auction service valves,

removal and installation.

by reversing the order of removal.

5-21