TM 5-6640-212-14
Table 5-2. Pyrometer Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. NEITHER PILOT LIGHT BURNS.
Check power supply, circuit breakers supplying power to
the unit.
a. Reset circuit breaker if open.
b. Check pilot light bulbs, replace as necessary.
2. GREEN PILOT LIGHT ON AT ALL TIMES.
Step 1.
Check for low line voltage.
If line voltage is low, adjust to proper level.
Step 2.
Check to see if meter is plugged into chassis all the
way.
Make visual check, if not plugged all the way into
chassis, make necessary adjustments.
Step 3.
Check if light source bulb is burned out.
If bulb is burned out, replace.
Step 4.
Check if photocell is defective.
Replace photocell.
3. RED PILOT LIGHT ON AT ALL TIMES.
Step 1.
Check for high line voltage.
Bring low voltage to proper level.
Step 2.
Check if flag on indicating pointer is free to pass between light and photocell.
If flag is not free to pass, make necessary adjustments.
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