Table 3-2. Electrical System Troubleshooting- Continued

TM 5-6640-213-14

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Check for defective wiring in main power switch.

Step 3.

Check wiring and correct.

3. NO POWER TO ANY COMPONENTS EXCEPT TIMER AND FAN.

Check fordefective K3 contactor, or defective wiring in contactor panel

or main power switch panel.

Repair or replace K3. Check wiring and correct.

4. FAN FAILSTOSTARTOR STOPS DURING OPERATION, IN "ALARM"

MODE OF OPERATION. (FAN LOCAL CONTROL SWITCH S3 OFF.)

Check for defective K4 relay, or defective wiring inmain power control

panel, or combustible alarm system or fan power circuit.

Repair or replace K4. Check wiring and correct.

5. NO LOCAL CONTROL OF FAN (FAN RUNS WITH LOCAL SWITCH S3 OFF.

AFTER 10-MINUTE AIR PURGE).

Step 1. Check for defective K2 relay, or combustible alarm system

malfunctioning causing K4 to be energized.

Repair or replace K2. Correct malfunction.

Step 2.

Check for defective wiring in fan circuit or main power control

panel.

Check wiring and correct.

6. POWER AVAILABLE TO ALL COMPONENTS PRIOR TO 10-MINUTE AIR

PURGE (MAIN POWER SWITCH S1 ON).

Check for defective timer.

Repair or replace timer.

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