(7)
Do not reset a tripped circuit breaker until you know the cause for the tripped circuit breaker and that the circuit breaker can be safely reset. Fires have occurred in which the tripped circuit breakers were reset without an examination of the cause.
(8)
Use this procedure to reset a tripped circuit breaker:
(a)
If you know that the circuit breaker is serviceable.
(b)
If this procedure is in agreement with your airline policy.
(c)
If you cannot determine the cause for the tripped circuit breaker.
(d)
If you cannot determine whether it is safe to reset the circuit breaker.
B. References
(1)
AMM (applicable procedure)
(2)
SWPM (applicable procedure)
(3)
WDM (applicable diagram)
C. Procedure
S 862-002
(1)
Attach a DO-NOT-CLOSE tag to the tripped circuit breaker.
(2)
Install a circuit breaker lock on the tripped circuit breaker.
S 862-004
(3)
If the tripped circuit breaker is one of three circuit breakers protecting a 3-phase circuit:
S 862-003
(a) Open the other two circuit breakers.
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(b)
Attach DO-NOT-CLOSE tags.
(c)
Install circuit breaker locks.
S 862-005
(4) Look in the aircraft logbook to find if there is recorded data about a "tripped" circuit breaker, such as:
(a)
The condition existing when the circuit breaker trip occurred.
(b)
The conditions existing when the circuit breaker was reset.
(c)
The results of resetting the circuit breaker.
S 862-006
(5) Do a visual check for damage to electrical wiring and system components related to the tripped circuit breaker. If necessary, refer to the Wiring Diagram Manual (WDM). Look for these types of damage:
(a)
Electrical shorting
(b)
Electrical arcing
(c)
Corrosion on the contacts of the electrical wiring and system components
(d)
Abrasion of the electrical wiring and system components
(e)
Cracks on the insulation of the electrical wiring
(f)
Split wires
NOTE: A split wire is when you can see the conductor through
____ the crack in the insulation of the electrical wiring.
(g)
Broken wires
(h)
Discoloration of the insulation of the electrical wiring
(i)
Fluid or dust contamination of electrical wiring and system components
NOTE: Contamination can be a fuel source during electrical
____
arcing.
(j) Metal shavings
NOTE: Metal shavings can cause electrical shorting.
____
S 862-007
(6) Make sure that there are no loose terminal connections.
NOTE: Loose terminal connections can be a source of electrical
____
arcing.
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(7) S 862-008If you find damage to the electrical wiring, refer to the Standard Wiring Practices Manual (SWPM) and repair the electrical wiring.
(8) S 862-009If you find damage to a system component, refer to the applicable Aircraft Maintenance Manual (AMM) procedure and replace the component.
(9) S 862-010Remove contamination and metal shavings if necessary.
S 862-011
(10)
Remove the DO-NOT-CLOSE tag(s).
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