TM 1-1520-238-T-6
9–570
9–277. FIRE DETR APU CIRCUIT BREAKER (CB11) – DOES NOT STAY CLOSED
9–277
OR 28 VDC IS NOT PRESENT AT (A76)J1-E
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer
One person to assist
References:
TM 1-1520-238-23
TM 1-1520-238-T-8
WARNING
Turn off power before detaching or
attaching wires and connectors. High
current 28 VDC or 115 VAC is present.
Failure to do so could result in death or
serious injury.
1. On pilot ELEC PWR panel, set BATT/EXT PWR
switch to EXT PWR.
Does FIRE DETR APU circuit breaker (CB11)
stay closed?
YES
Go to step 4.
NO
Go to step 2.
2. On pilot center circuit breaker panel, open FIRE
DETR APU circuit breaker (CB11). Set
BATT/EXT PWR switch to OFF. Check for short
between (A76)J1-E and ground.
Does short exist?
YES
Go to step 3.
NO
Refer to TM 1-1520-238-T-8 to
troubleshoot APU fire detection.
3. Detach wire at CB11-2. Check for short between
(A76)J1-E and ground.
Does short exist?
YES
Repair shorted wire between
CB11-2 and (A76)J1-E.
Go to paragraph 9–263.
NO
Replace FIRE DETR APU
circuit breaker (CB11)
(TM 1-1520-238-23).
4. Set BATT/EXT PWR switch to OFF. Check for
open between CB11-2 and (A76)J1-E.
Does open exist?
YES
Repair open wire.
Go to paragraph 9–263.
NO
Replace FIRE DETR APU
circuit breaker (CB11)
(TM 1-1520-238-23).
END OF TASK
