787 Flight Crew Operations Manual
DO NOT USE FOR FLIGHT
Electrical -
System Description
Copyright © The Boeing Company. See title page for details.
6.20.12 D615Z003-TBC
Load Inhibit and Load Shedding
There are two types of automatic load reduction that can occur to maintain power
for essential systems:
• Load inhibit – loads are inhibited at predefined operational phases. This is
because the affected system is not required, or additional power is
temporarily needed by another system.
• Load shed – loads are shed in the order of priority to stay within the
capacity of the available power sources.
The electrical synoptic shows a list of airplane systems affected by load shedding.
The affected system synoptic (AIR, FUEL, & HYD) also indicate equipment (in
white) that is inhibited or shed. Additionally, loads that are shed show “LOAD
SHED” text next to the affected equipment symbol.
IFE/PASS Seats and Cabin Systems/Utility Power
Electrical power to some non-essential loads can be controlled from the flight
deck. Two switches are provided for de-energizing these loads in an emergency.
One switch controls In-Flight Entertainment (IFE) and passenger seat power,
while the other controls galleys, lights, and other non-essential (utility) loads.
Pushing the IFE/PASS SEATS and CABIN/UTILITY switches de-energize these
systems.
Circuit Breaker Indication and Control (CBIC)
CBIC provides indication and control for Electronic Circuit Breakers (ECB), and
indication-only for Thermal Circuit Breakers (TCB). CBIC can be viewed on any
MFD, and operated using a CCD and MFK. Circuit breaker operational status is
depicted by a symbol. (Refer to CBIC Indication Symbology
in Chapter 6, Section
10, for additional information.)
The circuit breaker (CB) list can be sorted by the following categories using the
CBIC menu soft keys at the top of the display:
CBIC operation
Circuit breakers can be opened or closed using CBIC on the ground and in flight.
Note: Flight crew cycling (pulling and resetting) of circuit breakers to clear a
non-normal condition is not recommended unless directed by maintenance
or a non-normal checklist. In flight, flight crew reset of a tripped circuit
breaker is not recommended. (Refer to Non-Normal Checklist Operation
in QRH Chapter CI, Section 2, for additional information.)
• Flight Deck CB
• Open/Trip CB
• CB by State
• CB Search
• CB by ATA
• CB by location
• Recent Used CB
• CB Custom List
February 15, 2010
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