KLM MD-11 - Description and Operation; General; AC Power; Integrated Drive Generator (IDG)

MD-11 Flight Crew Operations Manual
k
Electrical Chapter Elec
Description and Operation Section 10
Elec.10.1
Elec.10 Electrical-Description and Operation
General
The ac and dc electrical systems are normally powered by three engine driven
Integrated Drive Generators (IDG). They may also be powered by an Auxiliary
Power Unit (APU) generator, or an external source through two external power
receptacles (main and galley).
The main external power plug connects external power to the main aircraft buses.
The galley external power plug connects external power to the galley buses.
During emergency operation the Captain's and First Officer's flight essential
equipment may be powered by a battery and by an Air-Driven Generator (ADG).
Distribution and control is normally done automatically by the Generator Control
Units (GCU) and the Electrical Power Control Unit (EPCU). In case of failure of
the automatic system the flight crew can control the electrical system manually
with controls on the forward overhead panel.
Due to the design of the electrical system, there are no special procedures for
operation in the manual mode.
The EPCU transmits system status and alerts to the Engine and Alert Display
(EAD) and the System Display (SD).
AC Power
Integrated Drive Generator (IDG)
During ground operations, ac power is supplied by two external power sources,
the APU generator, or by one or more of the three engine driven IDGs.
Each IDG is attached to each engine accessory gearbox by means of a Quick
Attach/Detach (QAD) adapter.
The IDG consists of a hydromechanical Constant Speed Drive (CSD) and an oil
cooled generator mounted side by side in a common housing. The CSD portion of
the IDG converts variable input speed from the engine accessory gearbox to a
constant output speed. This constant output speed drives the generator portion of
the IDG producing a constant 400-Hz frequency output.
The IDG will function paralleled or isolated.
Each IDG is able to supply sufficient power for operation of all essential electrical
systems.
October 02, 2006