AC SYSTEM
The AC electrical system is divided into
four subsystems: primary, auxiliary, exter-
nal, and emergency.
PRIMARY AC SYSTEM
The primary AC system normally supplies all of
the airplane electrical needs in flight. Each en-
gine drives an integrated drive generator which
consists of a constant-speed drive and a matched
generator. The generator supplies 3-phase, 115-
/200-volt, 400-Hz AC power and is rated at 30
kilovolt-amps (kva). Other components include
generator control units, generator line contac-
tors, and generator transfer contactors. The AC
system components locations and interconnec-
tion are shown in Figure 2-1.
Integrated-Drive Generators
(IDG)
Each IDG (Figure 2-2) is made up of a con-
stant speed drive (CSD) and an AC generator
that are assembled into one unit.
Constant-Speed Drive (CSD)
The CSD provides the mechanical interface be-
tween the engine accessory gearbox and the
generator. The CSD uses a self-contained oil
supply as an operating medium. Through a
series of hydromechanical devices, the vari-
able engine rpm is converted to a constant
12,000-rpm output to the generator. Thermal
and torque protection is provided by discon-
nect features built into the CSD.
2-2
CL 601-3A/R
FOR TRAINING PURPOSES ONLY
FlightSafety Canada
L t é e
L t d .
CL-600-2B16 PILOT TRAINING MANUAL
APU GEN
IDG 2
IDG 1
MAIN AC BUS
EXTERNAL AC
CONNECTION
ADG
MAIN ELECTRICAL
DISTRIBUTION PANEL
AC ESSENTIAL BUS
Figure 2-1. AC System Components Locations