TM 1-1520-238-T-6
9–186
9–28.
POWER XFMR RECT 1 CIRCUIT BREAKER (CB1) – DOES NOT STAY CLOSED
9–28
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
Equipment Conditions:
Ref
Condition
TM 1-1520-238-23
Access provisions –
L200 panel removed
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. Detach wires from (PS1)+28 VDC out POS
terminal. On pilot aft circuit breaker panel, close
POWER XFMR RECT 1 circuit breaker (CB1).
Does POWER XFMR RECT 1 circuit breaker
(CB1) stay closed?
YES
Go to step 2.
NO
Go to step 3.
2. Detach wires from T/R 1 terminal. Check for
short between wire ends and ground.
Does short exist?
YES
Repair shorted wires between:
T/R 1 and (PS1) + 28 VDC out.
Go to paragraph 9–23.
NO
Replace dc bus tie contactor
(TM 1-1520-238-23).
3. Open POWER XFMR RECT 1 circuit breaker
(CB1). Check for short between:
P3-S and ground,
P3-(TS) and ground,
P3-(US) and ground.
Does short exist?
YES
Repair shorted wires between :
CB1-A2 and P3-S,
CB1-B2 and P3-T,
CB1-C2 and P3-U.
Go to paragraph 9–23.
NO
Go to step 4.
4. Detach P6. Check for short between (A402):
J3-S and ground,
J3-T and ground,
J3-U and ground.
Does short exist?
YES
Repair shorted wires between :
(A402)J3-S and P6-F,
(A402)J3-T and P6-I,
(A402)J3-U and P6-B.
Go to paragraph 9–23.
NO
Replace T/R 1
(TM 1-1520-238-23).
END OF TASK
