ARMY TM 9-4120-380-14
NAVY EE-000-BA-MMA-010/7053-AC
AIR FORCE TO 35E9-136-21
Table 4-2. Unit Maintenance Troubleshooting - Continued
Malfunction
Test or Inspection
Corrective Action
5.
REDUCED HEATING CAPACITY
Step 1.
Check that all doors, windows and other openings in the room or enclosure are tightly closed
Tightly close all openings.
Step 2.
Check operation of thermostat (S2).
Test thermostat (paragraph 4.54). Replace thermostat if defective.
Disconnect input power before performing internal electrical
troubleshooting. Voltages used can KILL
Step 3. Check for loose or damaged electrical connections or damaged wires in wiring harnesses (see fig FO-2).
Tighten loose terminals.
Step 4. Check individual elements of heater (HR1 and HR2).
Test heater elements (paragraph 4.52). Replace element(s) if defective.
Step 5. Check operation of heater contactors (K4) and (K5).
Test contactor (paragraph 4.34). Replace contactor if defective.
Step 6. Check operation of heat fault thermostat (S8).
Test thermostat (paragraph 4.56) Replace thermostat if defective.
Step 7. Check operation of heat limit switches (S9) and (S10).
Test switches (paragraph 4.53) Replace switches if defective.
Step 8. Check operation of heat fault slave relay (K15).
Test relay (paragraph 4.40). Replace relay if defective.
Step 9. Check operation of heat fault relay (K10).
Test relay (paragraph 4.36). Replace relay if defective.
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