DIRECT SUPPORT TROUBLESHOOTING PROCEDURES - continued

TM 9-4120-430-14

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FAULT PROCEDURE 6.

INSUFFICIENT COOLING

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

INSUFFICIENT COOLING

Step 1.

Feel filter-drier to see whether it is cold to the touch, or is frosted or sweating.

If so, replace filter-drier. (Refer to WP 0051 00.)

Step 2.

Check evaporator coil for overall temperature.

If part of coil is relatively warm and evaporator inlet is sweaty or frosty, expansion valve or

distributor may be obstructed or damaged. (Refer to WP 0061 00.)

Step 3.

Check liquid sight indicator for bubbles or cloudiness, which indicates insufficient refrigerant.

Recharge system after checking for and repairing leaks. (Refer to WP 0043 00 through WP

0050 00.)

Step 4.

Check for high suction and low discharge pressure to see whether compressor is pumping. (Refer to

Table 1, WP 0050 00.)

Replace faulty compressor. (Refer to WP 0059 00.)

Step 5.

Check for high discharge pressure. (Refer to Table 1, WP 0050 00.)

Bleed off excess refrigerant.

FAULT PROCEDURE 7.

COMPRESSOR RUNS BUT DOES NOT COOL

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

COMPRESSOR RUNS BUT DOES NOT COOL

Step 1.

Check for continuity of temperature selector switch and thermostat (in COOL mode).

Replace defective switch. (Refer to WP 0026 00 and WP 0028 00.)

Step 2.

For S9160-18KH-1, check electrical rotation of power supply must be A-B for proper compressor

rotation.

Refer to schematic diagram (WP 0038 00) for proper connections.

For S9160-18KH-3, check electrical rotation of power supply. Must be A-B-C for proper

compressor rotation.

Step 3.

Check for excessively high temperature in conditioned area.

Close doors, windows or other openings. Insulate areas of high heat gain.

Step 4.

Check compressor for noisy operation, high suction pressure or excessively low discharge pressure

indicating leaky internal valves. (Refer to WP 0050 00 and Table 1, WP 0050 00.)

Replace compressor. (Refer to WP 0059 00.)

Step 5.

Check liquid sight indicator for bubbles indicating low charge of refrigerant.

Repair leaks or replace leaking component. Recharge system. (Refer to WP 0043 00 through

WP 0050 00.)

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