Eclipse 500 System Manual page 247

Section 10. Electrical
10.5.5 Electrical Buses
There are two battery buses and four equipment buses.
BATTERY BUSES
Hot Battery Bus
The hot battery bus is connected to the start battery and is powered at all times.
Its purpose is to provide power for overhead cabin and baggage compartment,
when the battery switches are off. These lights are on timers and depending on
the light, will automatically deactivate within five or fifteen minutes to prevent
battery depletion.
Battery Bus
The systems battery is connected to the battery bus and is powered when the
SYS BATT switch is on. The battery bus provides power to all four FADEC
channels, the left PFD and the left ACS through two mechanical circuit breakers
on the left switch panel, labeled LEFT PFD and LEFT ACS. The battery bus
voltage is indicated on the upper portion of the electrical synoptic, adjacent to the
battery bus contactor.
In the event that low voltage is detected on the battery bus, a BATT BUS VOLTAGE
LOW advisory message appears.
EQUIPMENT BUSES
Four equipment buses, left and right forward and left and right aft, supply power for
all aircraft systems. During normal operation the ACS divides the buses into a
left/right configuration, with the left forward and left aft buses receiving power from
the left generator, and the right forward and right aft buses receiving power from the
right generator.
The left and right aft bus voltages are indicated on the lower portion of the electrical
synoptic, adjacent to the left and right aft bus segments.
In the event that low voltage is detected on any of the equipment buses, one of the
following caution messages will appear.
L AFT BUS VOLTAGE LOW
R AFT BUS VOLTAGE LOW
L FWD BUS VOLTAGE LOW
R FWD BUS VOLTAGE LOW
BUS TIE CONTACTOR
The bus tie contactor electrically ties together or isolates the left and right aft buses.
The bus tie contactor is controlled by the BUS TIE switch on the left switch panel.
During normal operation with the BUS TIE switch in the AUTO position, the ACS
controls the position of the bus tie contactor; however it can be manually opened by
placing the BUS TIE switch in the OPEN position. Should the bus tie contactor
become stuck closed, a BUS TIE FAIL caution message appears.
In AUTO, the bus tie contactor is open during normal operations, and will
automatically close if any of the following are powering the airplane:
Single generator
Battery
External power
All aircraft buses are powered in the above situations and when operating on a single
generator or external power, both batteries are being charged.
Version 2.0 April 2007
Copyright © — Eclipse Aviation Corporation
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