Electrical System

Question 1

What are the AC and DC volts?

Answer 1

115 Volts AC

28 volts DC

Question 2

How does the AC electrical power is provided?

Answer 2

two engine-driven generation systems.

Question 3

Each engine-driven generation systems have:

Answer 3

integrated drive generator (IDG)

generator control unit (GCU).

Question 4

What is the connections of auxiliary power unit (APU) generator with integrated Drive generators?

Answer 4

back AC power source to replace either or both IDGs.

Question 5

What is the back In the event of total AC power loss?

Answer 5

AC power is available from an in-flight air-driven generator (ADG).
The ADG assembly is stowed in a compartment on the right side of the nose section.

Question 6

How does the AC power transformed to DC power?

Answer 6

DC power is supplied by five transformer rectifier units (TRU)
main battery and APU battery.

Question 7

How does the Power for starting the APU is provided?

Answer 7

by the APU battery.

Question 8

How do we connect the AC and DC power to the appropriate buses and components?

Answer 8

13 junction boxes in the aircraft, are used for connecting.

Question 9

Where are the locations of external AC power?

Answer 9

AC power through receptacle located on the forward right side of the fuselage.
DC Power through a receptacle located on the aft right side of the fuselage.

Question 10

Where are the AC and DC system control switches?

Answer 10

The electrical power services panel (EPSP) in the flight compartment, and the external service panel on the right forward fuselage

Question 11

Where do the Electrical system warnings and cautions are displayed?

Answer 11

on the EICAS primary page.

Question 12

Locations of 
Main Battery and APU Battery 
IDG 1 and 2
External DC Location
TRANSFORMER RECTIFIER UNITS
EXTERNAL AC CONNECTION
AIR DRIVEN GENERATOR

Answer 12