AIRPLANE
OPERATIONS
MANUAL
ELECTRICAL
REVISION 36
2-05-05
Page
9
Code
01
AOM-145/1114
ELECTRICAL DISTRIBUTION LOGIC
Many different configurations are available in the Electrical Distribution
Logic (EDL) to suit any particular situation. The EDL’s architecture is
symmetrical and the operational logic sequence for EDL 1 is the same
as for EDL 2. EDL 1 is composed of DC Bus 1, Shed DC Bus 1,
Essential DC Bus 1 and Hot Bus 1. The EDL 2 is composed of DC Bus
2, Shed DC Bus 2, Essential DC Bus 2 and Hot Bus 2.
The Central DC Bus primary function is to connect the APU generator
or GPU to the load buses through the Bus Tie Contactors (BTC). The
Central DC Bus also provides bus interconnections in case of
asymmetrical configuration, such as generators failure or engine
shutdown.
The Electrical Distribution Logic (EDL) differs depending on whether
the airplane is on the ground or in flight. In flight, some buses are
deenergized, depending on the power source available.
On the ground, all the DC buses are energized if at least one of the
following conditions occurs:
At least three generators are on.
The GPU is on and connected to the airplane.
At least one generator is on, and the Shed Buses Selector Knob is
set to OVRD position.
The DC distribution table below shows the Electrical Distribution Logic
configuration according to the conditions of the generators.
DC DISTRIBUTION TABLE
CONDITION RESULTS
4 or 5 Generators On
Two isolated left and right electrical
networks with all buses energized.
3 Generators On
Both electrical networks interconnected
through Bus Tie Contactors with all buses
energized.
1 or 2 Generators On
Both electrical networks interconnected
through Bus Tie Contactors with shed buses
deenergized.
Loss of all
Generators
Batteries to supply the Essential Buses
(in-flight condition only).
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