FlightSafety LEARJET 45 - AC POWER

Figure 2-21 illustrates the status of the con-
tactors and busses after engine start with one
engine-driven generator on-line. The essential
bus contactors have closed and the left isola-
tion contactor opened. Also, the contactors
to the non-essential busses have closed. The
bus-tie contactor remains closed at this point
so that both generator busses are powered by
the single generator.
Figure 2-22 illustrates the electrical system
contactor and bus status for normal flight con-
ditions. After the second engine-driven gen-
erator is brought on-line, the bus-tie opens
and will remain open as long as both genera-
tors remain on-line and the bus tie is not man-
ually selected closed.
AC POWER
GENERAL
As part of the anti-ice protection system, left
and right windshield heaters are powered by
two, left and right engine-driven alternators.
The alternators are mounted to the front of
the engine accessory drive box, next to the
starter/generator, and operate from 6,000 to
12,000 rpm (Figure 2-7).
The alternators supply 200 VAC, 200-400 Hz
at a maximum of 5 KVA single phase output.
The alternator output is controlled by a sepa-
rate control unit that contains the monitor cir-
cuitry for the windshield. There are no
provisions for directly monitoring alternator
output on the EICAS displays, but loss of AC
power from an alternator would be detected by
failure of windshield anti-ice.
The output of the alternators is only used by
the windshield anti-ice.
LEARJET 45 PILOT TRAINING MANUAL
2-27
FOR TRAINING PURPOSES ONLY
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