Electrical Systems

Question 1

CA - name the different sources of AC power available

Answer 1

IDG 1, IDG2, APU, EXT AC, ADG

Question 2

FO - what is required for the green AVAIL lamp to illuminate in the AC EXTERNAL switch light?

Answer 2

power is connected and its ready to use

Question 3

CA - after turning on the battery master switch but before establishing AC power, is it normal for the AC ESS XFER switch light to be illuminated? what does it mean?

Answer 3

AC ESS XFER light illuminated means that the ESS bus is powered by AC BUS 2

Question 4

FO - describe the components of the IDG

Answer 4

CSD and Generator

Question 5

CA - under what conditions will the IDG fault caution message be displayed

Answer 5

High oil Temp
Low Oil Pressure
no such caution message

Question 6

FO - is the IGD still producing power when the IDG FAULT caution message is displayed?

Answer 6

only if it was not automatically disconnected (overtemp or over torque) - WHITE DISC light,

Question 7

CA - will the IDG DISC switch light be illuminated with the engine shutdown at the gate if the IDG is disconnected?

Answer 7

NO - reference IDG MEL

Question 8

FO - As directed by the QRH, IDG 1 is disconnected, is this something the crew can reverse?

Answer 8

NO

Question 9

CA - describe the power priority for AC BUS2

Answer 9

GEN2, APU, GEN 1, EXT AC

Question 10

FO - what does the AUTO XFER caution message mean?

Answer 10

The automatic transfer of power source was attempted but failed.

Question 11

CA - Is there a difference between the meaning of the AUTO XFER caution message and the AUTO XFER OFF status message.

Answer 11

yes- the caution means the automatic transfer has failed where the status means the automatic mode has been deselected.

Question 12

FO - what would cause the the AC utility busses to be load shed on the ground?

Answer 12

Single generator operations on the ground
flaps greater than 0
service door is closed
passenger door is closed

Question 13

CA - what would cause the AC UTIL busses to load shed in flight?

Answer 13

Single GEN operations

Question 14

FO - under what conditions with the ADG automatically deploy

Answer 14

Loss of all AC power
last source of AC power was internal
Parking brake not set
weight off wheels is sensed

Question 15

CA - what busses and or components will be powered under ADG power

Answer 15

• ADG BUS
• AC ESS BUS
• ACMP 3B

Question 16

FO - what airspeed limitations exist for the ADG?

Answer 16

WET - 250KIAS

DRY - MMo/VMo

Question 17

CA - after restoring normal AC power, how is the AC ESS bus transferred to the normal AC power distribution system?

Answer 17

Stow the handle, and push the PWR TXFR OVERRIDE button on the ADG panel

Question 18

FO - name the different sources of DC power available.

Answer 18

2 batteries and 5 TRU’s

Question 19

CA - what are the minimum voltages for the APU and Main batteries prior to starting the APU

Answer 19

22v each

Question 20

FO - ground operations with only DC power are limited to how long

Answer 20

5 minuites

Question 21

CA - what is the amp rating for the TRUs in the 200

Answer 21

100A

Question 22

FO - what is the amp rating for the TRUs in the 700/900?

Answer 22

120A

Question 23

CA - is TRU #2 capable of supplying power to DC bus 1 in the event of a TRU #1 failure?

Answer 23

yes, through tie 1 and 2

Question 24

FO - are all the DC ties capable of automatically being closed?

Answer 24

no, only tie 1 and tie 2. ESS tie in manual only