AIRPLANE
OPERATIONS
MANUAL
ELECTRICAL
MARCH 28, 2002
2-05-15
Page
3
Code
01
CONTROLS AND INDICATORS
ELECTRICAL SYSTEM PANEL
1 - GENERATOR BUTTON
− Connects (pressed) or disconnects (released) the associated
generator to/from the respective DC Bus.
− Pressing and depressing the Generator Button causes all GCU
latches protection circuits to be reset if the associated generator
is running.
− A striped bar illuminates inside the button when it is released.
2 - GROUND POWER UNIT BUTTON
− Connects (pressed) or disconnects (released) the GPU to/from
the electrical system.
− A GPU AVAIL inscription illuminates, in the upper half of the
button, when the GPU is properly connected to the airplane
receptacle and ready to supply power. The GPU AVAIL
inscription extinguishes when the button is pressed and the
external power is connected to the electrical network.
− A striped bar illuminates inside the button when it is pressed.
3 - APU STARTER GENERATOR BUTTON
− Connects (pressed) or disconnects (released) the APU starter
generator, when APU RPM is above 95%, plus 7 seconds.
− A striped bar illuminates inside the button when it is released.
4 - BATTERY SELECTOR KNOB
OFF - Respective battery contactor is kept open, disconnecting
the associated battery from the electrical system.
AUTO - The actuation of the respective battery contactor is
controlled according to the Electrical Distribution Logic.
5 - ESSENTIAL POWER BUTTON (guarded)
− When pressed the system overrides the automatic transfer to
the electrical emergency circuitry, connecting the batteries
directly to essential buses, regardless of any other command
from the Electrical Distribution Logic.
− When released, the power contactors operate automatically
according to the Electrical Distribution Logic.
− A striped bar illuminates inside the button when it is pressed.
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