TM 1-1520-238-T-6
9–506
Change 5
9–233. CIRCUIT PROTECTION SYSTEM (DC ESSENTIAL BUS 3 – PILOT STATION) –
9–233
MAINTENANCE OPERATIONAL CHECK (cont)
Task
Result
Step h. (cont)
If MISSION RKT ELEX circuit breaker (CB47) does
not stay closed, go to paragraph 9–241.
If ASE DC circuit breaker (CB28) does not stay
closed, go to paragraph 9–242.
If ECS ICE DET circuit breaker (CB68) does not stay
closed, go to paragraph 9–243.
If ECS BLADE DE-ICE CONTR circuit breaker
(CB83) does not stay closed, go to paragraph 9–244.
If ECS BLADE DE-ICE circuit breaker (CB85) does
not stay closed, go to paragraph 9–245.
If STAB AUTO DC circuit breaker (CB3) does not
stay closed, go to paragraph 9–246.
If MISSION EL DC circuit breaker (CB93) does not
stay closed, go to paragraph 9–247.
If NAV EGI circuit breaker (CB97) does not stay
closed, go to paragraph 9–248A.
If MISSION DTU circuit breaker (CB98) does not stay
closed, go to paragraph 9–248B.
NOTE
For helicopters with BUCS deactivated, the ASE BUCS circuit breaker shall be
open and locked.
i. On helicopters with BUCS activated (ACA),
close and check that ASE BUCS circuit
breaker stays closed.
If ASE BUCS circuit breaker (CB77) does not stay
closed, go to paragraph 9–248.
j. On pilot ELEC PWR panel (fig. 9–182), set
BATT/EXT PWR switch to OFF and detach
P2.
k. On pilot ELEC PWR panel, set BATT/EXT
PWR switch to EXT PWR.
l. Check for 28 VDC at P2-k.
If 28 VDC is not present, go to paragraph 9–236.
m. Check for 28 VDC at P2-J.
If 28 VDC is not present, go to paragraph 9–239.
n. On pilot ELEC PWR panel (fig. 9–182), set
BATT/EXT PWR switch to OFF. Attach P2
and detach P1.
o. On pilot ELEC PWR panel, set BATT/EXT
PWR switch to EXT PWR.
p. Check for 28 VDC at P1-46.
If 28 VDC is not present, go to paragraph 9–237.
