TM 5-4520-253-13
Table 3-3. Unit Maintenance Troubleshooting -- Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
RESET CIRCUIT BREAKER TRIPPED REPEATEDLY WHEN HEATER-OFF-FAN SWITCH
IS SET TO HEATER
Step 1.
Check flame switch and bracket assembly for continuity.
a.
b.
c.
d.
e.
For Model UH-68G1, check receptacle (1) and plug (2) in harness connected
to PC board assembly (3). Plug should be securely connected to receptacle.
If receptacle (1) or plug (2) is damaged or cannot be securely
connected, forward heater to intermediate maintenance for
replacement.
Remove two screws (4) and lock washers (5). Pull flame switch and bracket
assembly (6) out of opening (7) in heater bulkhead.
Disconnect red and violet wires from flame switch (8). Using volt ohmmeter,
place one probe against each terminal of flame switch (8). Meter should
indicate zero resistance.
Heat bottom of flame switch (8) to 130°F (54°C) and place probes on
terminals. Switch should snap (open) and meter should indicate infinite
resistance.
Connect red and violet wires to flame switch (8).
3-34
Change 2
