Electrical

Question 1

What does having standby power in off do?

Answer 1

It cuts of all sources of power to the ac and dc stby buses.

Question 2

What does the standby power switch in auto do?

Answer 2

It gives give the authority to the main ac and dc buses to power the battery bus, stby ac and dc busses. Then it allows the battery to power them as a back up.

Question 3

What does the standby power switch in bat position do?

Answer 3

It cuts off the main ac and dc power going to the stby ac and dc busses. The battery becomes the only source of power to these busses.

Question 4

How many sources of ac power do we have?

Answer 4

4
2 engine gens
Apu gen
External power

Question 5

How do you disconnect an idg?

Answer 5

Idg disconnect switch

Question 6

Can you reconnect and idg in flight?

Answer 6

No

Question 7

How many tru do we have?

Answer 7

2

Question 8

What powers the utility buses?

Answer 8

Respective ac buses

Question 9

What happens to the utility busses if you become single gen in flight or on takeoff?

Answer 9

They both shed

Question 10

Can you reconnect the shed utility busses in flight?

Answer 10

Yes by getting another gen back online

Question 11

How can you reset both the tripped utility buses on the ground?

Answer 11

By having one or both thrust levers at idle and just turning off and on the bus switches

Question 12

What can happen to the utility if you advance the thrust levers for takeoff with out having the engines running?

Answer 12

advancing both thrust levers before engine start or after engine shutdown can cause a trip off of the utility buses.

Question 13

Explain the overload load shedding logic?

Answer 13

If the apu or the external power is powering the whole aircraft electrical system and an overload happens, both the utility busses trip off.

If two separate gens are powering the system such as an engine on one side and apu on the other and an over load happens, only utility bus on the side the overload happened trips off.

Question 14

Explain the engine start load shedding logic?

Answer 14

When the apu is supplying both elctric and pneumatic for the who airplane and and engine is being started, both utility busses get shed.

Once one engine is started, both utility busses come back on.

Then when you start the next engine, only the utility bus on that side shed till the engine is up and running.

Question 15

How many ac bus ties do we have?

Answer 15

2

Question 16

How many dc bus ties do we have?

Answer 16

1

Question 17

What is the power acceptance logic?

Answer 17

Onside gen
Apu
Offside gen

Question 18

Normally what bus powers the captains flight instruments?

Answer 18

Left main ac bus

Question 19

Normally what bus powers the first officers flight instruments?

Answer 19

Right main ac bus

Question 20

Does external power have priority over all the other power sources?

Answer 20

Yes

Question 21

Which are the only 2 power sources for the ground handling bus?

Answer 21

The apu or external power

Question 22

Does the apu or external power switches need to be selected for the ground handling bus to be powered?

Answer 22

No. They just have to be available

Question 23

What bus powers the ground service bus?

Answer 23

Right main ac bus

Question 24

What is the primary source of dc power?

Answer 24

2 tru

Question 25

What buses power the tru?

Answer 25

Respective main ac buses

Question 26

What powers the main dc buses?

Answer 26

The respective tru

Question 27

How many batteries do we have?

Answer 27

2

Question 28

What bus charges the battery chargers?

Answer 28

Ground service bus

Question 29

How many battery chargers do we have?

Answer 29

2

Question 30

What directly powers the hot battery bus?

Answer 30

Battery

Question 31

What is the function of the stby busses?

Answer 31

The standby buses power many instruments and systems essential for safe flight during all nor-mal and non-normal operations.

Question 32

Explain engine start load shedding?

Answer 32

When apu is suppling bleed and electrical power to start the engines, both utility buses are shed during the first start. During starting the other engine, only the utility bus on that side is shed.

Question 33

What happens if you are in the air or on the ground and all the ac busses are being powered by separate gens and an overload happens on one of the gens?

Answer 33

If a separate generator is supplying each main AC bus (on the ground or in the air), only the utility buses associated with the overloaded generator is shed.