TM 1-1520-238-T-7
(11–377 blank)/11–378
Change 5
11–92. STAB AUTO AC CIRCUIT BREAKER – DOES NOT STAY CLOSED
11–92
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer
References:
TM 1-1520-238-T-6
TM 1-1520-238-23
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. Open STAB AUTO AC circuit breaker
(A76)CB2. Detach P1 from (A402)J1. Check for
short between P1–36 and ground.
Does short exist?
YES
Refer to TM 1-1520-238-T-6
to troubleshoot circuit protection
system (ac essential bus 1 –
pilot station).
NO
Go to step 2.
2. Detach P431 from (A402)J27. Check for short
between (A402)J1–36 and ground.
Does short exist?
YES
Repair shorted wire between
(A402):
TB3–17–J and J1–36,
TB3–17–K and J27–A8,
TB3–17–L and J27–A12.
Go to paragraph 11–88.
NO
Go to step 3.
3. Detach P985 from (A637)J1 and P989 from
(A638)J1. Check for short between:
P431–A8 and ground,
P431–A12 and ground.
Does short exist?
YES
Repair shorted wire between:
P431–A8 and P989–A,
P431–A12 and P985–A.
Go to paragraph 11–88.
NO
Go to step 4.
4. Check for short between (A637)J1–A and
ground.
Does short exist?
YES
Replace STAB CONT UNIT 1
(A637)
(TM 1-1520-238-23).
NO
Replace STAB CONT UNIT 2
(A638)
(TM 1-1520-238-23).
END OF TASK
