Falcon 900 B Electrical

Question 1

Can a GPU be used to charge the batteries?

Answer 1

No, unless the optional battery charging system is installed.

Question 2

How many electrical buses?

Answer 2

8 - Battery bus, starter bus, left main bus, right main bus, bus A1, bus A2, bus B1, bus B2.

Question 3

Are the left and right main buses normally tied?

Answer 3

No. Although it must be selected closed to start the APU and, if a GPU is connected, the bus tie automatically closes.

Question 4

To which bus are the two voltmeters connected?

Answer 4

To the right and left main buses. (24-5)

Question 5

What are the volts and amps of each nicad battery?

Answer 5

Nicad, 26 volts, 23 amp hours (24-7)

Question 6

How are the batteries vented on the ground/in the air?

Answer 6

Fan on the ground, fan turns off in the air and ventilation provided by low pressure in the vent duct created by shape of protruding vent exhaust on the skin of the aircraft

Question 7

What switch is directly associated with the battery switch?

What would cause these switches to trip?

Answer 7

Make-and-break switches (24-8)

Excessive current flow to the batteries

Question 8

What 4 items are powered when the battery bus is connected?

Answer 8

F.R.O.G.  
F - Fire extinguishing
R - Refuel panel
O - Outboard Slats Normal system 1
G - Generator excitation (24-9)

Question 9

How are buses A1 and A2 powered?

Answer 9

Left Main bus - when the left battery is connected and the battery switch is on and the power switch is in the NORMAL position, it provides power to the left main bus - no power goes to the Right main if the bus tie is open. (24-9)

Question 10

How are buses B1 and B2 powered?

Answer 10

Right Main bus - when the Right battery is connected, the battery switch is on and the power switch is in the NORMAL position, it provides power to the Right main bus. - no power goes to the Left main bus if the bus tie is open (24-9)

Question 11

How many amps/volts are produced by the APU generator?

Answer 11

300 amps, 28.5 volts

Question 12

Do the buses need to be manually tied in order to start the APU?

Answer 12

Yes - using the switch on the overhead panel.

Question 13

What protection is between the RH and LH main buses?

Answer 13

A 225 amp current limiter. (24-3)

Question 14

To which main bus is the APU connected?

Answer 14

Right Main bus - but when the APU is started the bus tie must be closed so the APU powers both main buses once it is running. (24-15)

Question 15

Does the APU charge the batteries?

Answer 15

Yes

Question 16

What high voltage would cause the GCU to kick off a generator from the electrical system?

Answer 16

32 volts

Question 17

What systems will automatically load shed if one generator goes off line?

Answer 17

galley, lavatory, cabin entertainment

Question 18

Does the APU help in the start of an engine?

Answer 18

Yes. Unless SB 315 is installed on the aircraft. (see FS manual pg 24-18 left column, top paragraph.)

Question 19

In flight normal operation which generator(s) power the left main bus?

Answer 19

Gens 1 & 3 which in turn power the A1 and A2 buses.

Question 20

In flight normal operation which generator(s) power the right main bus?

Answer 20

Gen 2 which in turn power the B1 and B2 buses (24-23)

Question 21

If engine No. 2 is shut down what must be done to power the Right Hand Main bus?

Answer 21

Close the bus tie. If this is not done then only the RH battery will power the bus.

Question 22

What is the maximum amperage rating for a GPU powering the airplane?

Answer 22

1200 amps

Question 23

What happens if the GPU puts out too much voltage for the aircraft?

Answer 23

An over voltage relay will disconnect the GPU from the aircraft. If the problem is rectified then a GPU reset button can be pressed to reset the system. This button is on the main electrical box in the hell hole on the Left side.

Question 24

Is it normal for BAT 1 and BAT 2 lights to come on when a GPU is connected to the aircraft?

Answer 24

Yes, the batteries are automatically disconnected from the aircraft when the EXT POWER switch is selected on the overhead panel

Question 25

If a GPU and APU are running at the same time which of the two will power the aircraft?

Answer 25

The GPU - (24-26 left column at the bottom)

Question 26

If all three engines are running and the GPU is still connected to the aircraft is it normal for the GEN 1, GEN 2, and GEN 3 lights to be on?

Answer 26

Yes, until the EXT POWER switch is changed to NORMAL. Then they will extinguish. 24-26

Question 27

What are the 4 red circuit breakers on the overhead CB panel?

Answer 27

These breakers are powered by either A1 bus or B1 bus. If one of the buses fails the other bus automatically takes over.

Question 28

Is it normal for the APU GEN light to come on during engine start?

Answer 28

Yes. When the APU is assisting the start of an engine the power from the APU generator will go to the engine start and temporarily be disconnected from the normal distribution system. pg 24-18

Question 29

What should done if a generator switch is accidentally turned off in flight (or anytime the engines are at full power)?

Answer 29

The engine associated with the affected generator should be brought to idle, the generator switch turned back on and then bring the engine power back to normal. If the generator is brought back on line with the engine at full power it could shear the generator connecting shaft.

Question 30

What turns on the battery blower fan on the ground?

Answer 30

BAT 2 switch and the power selector switch in the normal position. If the APU is running then the APU provides cooling air in lieu of the battery fan. (24-7)

Question 31

Which battery connects directly to the start bus when it is plugged in?

Answer 31

Battery #1 only. Battery two is only connected to the start bus when the engines or APU are started and battery two contactor relay is closed.

Question 32

What can cause the left and right buses to be tied even if the bus tie switch on the overhead panel is in flight normal (buses separated) position?

Answer 32

If the battery two contractor welds closed.

Question 33

What powers the battery bus if the GPU is connected and the power switch is in the EXT POWER position?

Answer 33

The GPU powers the entire system. (24-15)

Question 34

Is it normal for the APU GEN light to come on during the start of the main engines?

Answer 34

Yes, because the APU generator is temporarily disconnected from the aircraft's main electrical systems in order to help with the start. (24-18 see NOTE)

Question 35

Does the APU generator provide power to the electrical system if the engine generators are running?

Answer 35

Yes, as long as the bus tie is closed. As soon as the bus tie is opened the APU shuts down. (24-21)

Question 36

Where are the make and break switches associated with the battery switches on the overhead panel?

Answer 36

They are in the main electrical box in the maintenance bay at the back of the aircraft. (Figure 24-20)

Question 37

What are some of the systems that are powered by both the A1 and B1 bus for redundancy? (think red circuit breakers) What is an other name for these systems?

Answer 37

1. Warning panel 2. Warning lights test 3. Emergency lights 4. Aileron Feel 5. Fire Panel 6. Baggage compartment door detector These are called priority circuits. (Fig 24-22)

Question 38

Battery 2 contractor connects battery 2 to the __________.

Answer 38

Starting bus