Electrical Power Systems

Question 1

Primary Electrical system voltage?

Answer 1

28 VDC

Question 2

Battery voltage?

Answer 2

24v

Question 3

What is the “hot battery bus”?

Answer 3

The hot battery bus supplies power to essential equipment when the battery and generators are not on

Question 4

How is the “main bus” power controlled?

Answer 4

Via the battery ON-OFF relay switch.

Question 5

How many starter-generators?

Answer 5

two. One for each engine

Question 6

Where are the batt and gen switches located?

Answer 6

underneath the gang bar in the left subpanel

Question 7

Minimum battery voltage when using external power:

Answer 7

20v

Question 8

Where is the external power plug located?

Answer 8

Under the right wing outboard of the nacelle

Question 9

Explain the format of the loadmeters?

Answer 9

The top scale shows load percentage of 250 amps (for each generator). There is a button that can be depressed to show the bus voltage

Question 10

Explain how redundancy is achieved with the DUEL FED SUB-BUSES.

Answer 10

It’s in the name - dual fed. 1 - 4 is dual fed by the L and R generators, so if one fails the other will still provide power.

Question 11

Starter limitations:

Answer 11

40 seconds - ON, then 60 seconds - OFF. you can do this sequence a second time. On the third time - 40 seconds ON, then 30 minutes - OFF.