Table 4-1. Troubleshooting - continued

TM 5-4120-339-14

Table 4-1. Troubleshooting (continued)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

FANS DO NOT OPERATE (continued)

Step 4.

Continuity check fan motor circuit (figure 3-8).

Replace or repair defective wiring.

11.

UNIT DOES NOT OPERATE IN HEATING MODE

Step 1.

Continuity check heater circuit (figure 3-8).

Replace or repair defective wiring.

Step 2.

Inspect and test selector switch (paragraph 3-12b).

Replace damaged or defective selector switch.

Section III. Maintenance Procedures

4-4.

GENERAL MAINTENANCE PROCEDURES.

a. Removing and Installing Panels and Grilles. Direct Support Maintenance of air conditioner components

normally requires the removal of panels and grilles to provide access to the interior of the unit, and installation of these

panels and grilles after maintenance has been accomplished. Refer to figure 3-3 for required removal and installation of

panels and grilles during accomplishment of Direct Support Maintenance.

b. Soldering and Brazing.

(1) Use a silver solder on all soldered connections of the copper tubing. Silver solder with a 50 percent silver

capacity and a melting point of approximately 1300F (704C) is recommended.

(2) Continually pass dry nitrogen through the tubing or connections being soldered or brazed to prevent the

formation of harmful copper oxides.

Checking for Refrigerant System Leaks.

(1) Turn selector switch to "OFF" position and disconnect the air conditioner from the electrical power source.

(2) Refer to figure 4-5 and install pressure gages.

4-7