Electrical

Question 1

How many generators (including APU) can power all electrical needs?

Answer 1

1

Question 2

In flight, during generator failure, what is automatically shed?

Answer 2

Main galley power

Question 3

What is the main difference between when Gen 1 fails versus Gen 2?

Answer 3

Gen 1 is connected to the Essential Bus and Shed while Gen 2 requires the AC ESS FEED button depressed

Question 4

When RAT deploys, what does it power?

Answer 4

AC and DC ESS BUS and SHED

Question 5

In an emergency what does BATT 1 power?

Answer 5

AC ESS BUS through inverter

Question 6

In an emergency what does BATT 2 power?

Answer 6

DC ESS BUS

Question 7

What are the electrical priorities?

Answer 7

G enerators
E xternal Power
A pu generator
R am air turbine
B atteries

Question 8

What are the capacities of the generators and the APU?

Answer 8

90 KVA
3 phase
115-200 V
400 Hz

Question 9

What are the capacities of the emergency generator?

Answer 9

5 KVA
3 phase
115-200 V
400 Hz

Question 10

What do the (TR) transformer-rectifiers do?

Answer 10

Convert AC to DC

Question 11

When will you see a green arrow connected to the battery?

Answer 11

only when current is >1 amp

Question 12

What are the limitations for the IDG FAULT buttons?

Answer 12

Do not depress more than 3 seconds.
Engine must be running or windmilling
Can be reset on ground only

Question 13

When will you get the IDG FAULT light on?

Answer 13

High IDG oil temp

Low IDG oil pressure

Question 14

When will the batteries start charging?

Answer 14

<26.5V

Question 15

When will the battery contactors close?

Answer 15

AC BUS 1&2 not powered by other sources (no EMER GEN during flight, worst case)

Question 16

When will the auto batt cut-off?

Answer 16

Ground
BAT in AUTO
AC power source N/A
Batt voltage low
(reset by cycling BAT buttons)

Question 17

How long are batteries prevented from charging after APU start?

Answer 17

30 minutes

Question 18

During preflight, what white lights should be present on the ELEC panel?

Answer 18

None!

Question 19

When you turn on the battery what is the max charging current allowed?

Answer 19

<60A and decreasing within 10 seconds

Question 20

What tells you that the APU is powering the AC?

Answer 20

AVAIL light on the APU START button AND AVAIL light on the EXT POWER button

Question 21

When you start engine 2, what happens to the bus tie?

Answer 21

Opens, APU now powers BUS 1 and Generator powers BUS 2

Question 22

RAT & EMER GEN FAULT light is on, what does this mean?

Answer 22

The RAT takes 8 seconds to spool up before coming on-line, during this time you are running off the batteries.

Question 23

What is the min speed for the RAT to function?

Answer 23

140kts

Question 24

During landing, at what speed does the EMER GEN become unavailable?

Answer 24

125kts

Question 25

What happens below 50kts during total electrical failure?

Answer 25

All displays blank
Braking and engine control
VHF1
NO nosewheel steering