VENTILATION FANS (SUPPLY AND EXHAUST)

TM 55-1905-223-24-17

Table 3-1. Troubleshooting

Malfunction

Test or Inspection

Corrective Action

VENTILATION FANS (SUPPLY AND EXHAUST)

WARNING

Make sure a fan is not in a stalled condition before attempting

maintenance. Severe injury could result if fan operates while

being worked on.

Excessive noise or vibration.

STEP 1

Check for impeller out of balance, worn, or corroded. Replace impeller or fan as required

(paragraph 3-17, 3-19, 3-21, 3-22, or 3-23 or 3-24).

STEP 2. Check for worn or defective bearings. Replace bearings as required (paragraphs 3-17

Fan does not operate.

STEP 1

Check for defective fan motor. Replace fan motor (paragraph 3-18, 3-20, 3-21, 3-22, 3-23,

AIR CONDITIONING

Higher than normal operating head (discharge) pressure.

STEP 1

Check to see if refrigerant is overcharged.

a. Remove excess refrigerant:

NOTE

Self-contained units are not equipped with discharge service

valve for attaching high pressure hoseline of portable gauge to

obtain discharge pressure.

A/C-1 and 3 are self-contained units.

(1) Shut down compressor and remove front cabinet panel for access to compressor.

3-4