TM 1-1520-238-T-6
9–450
9–196. ECS CANOPY ANTI-ICE CIRCUIT BREAKER (CB78) – DOES NOT STAY CLOSED OR
9–196
115 VAC IS NOT PRESENT AT P2-c, P2-d, P2-e
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer
References:
TM 1-1520-238-23
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 ECS CANOPY ANTI-ICE circuit breaker
(CB78) stay closed?
YES
Go to step 4.
NO
Go to step 2.
2. With BATT/EXT PWR switch to OFF. Check for
short between:
P2-c and ground,
P2-d and ground,
P2-e and ground.
Does short exist?
YES
Go to step 3.
NO
Refer to TM 1-1520-238-T-8 to
troubleshoot environmental
control system.
3. Detach wire at CB78-A2, CB78-B2 and
CB78-C2. Check for short between:
P2-c and ground,
P2-d and ground,
P2-e and ground.
Does short exist?
YES
Repair shorted wire.
Go to paragraph 9–189.
NO
Replace ECS CANOPY
ANTI-ICE circuit breaker (CB78)
(TM 1-1520-238-23).
4. Open CB78. Set BATT/EXT PWR switch to OFF.
Check for open between:
P3-D and CB78-A1,
P3-E and CB78-B1,
P3-F and CB78-C1,
P2-c and CB78-A2,
P2-d and CB78-B2,
P2-e and CB78-C2.
Does open exist?
YES
Repair open wire.
Go to paragraph
9–189.
NO
Replace ECS CANOPY
ANTI-ICE circuit breaker (CB78)
(TM 1-1520-238-23).
END OF TASK
