Electrical

Question 1

The HMG provides power to

Answer 1

5 Buses

L and R ESS DC Buses thru the AUX TRU
L and R Standby AC Buses
EMER ESS AC Bus thru the E-Inverter

Question 2

What is the normal AC power source for the AUX TRU and ESS AC bus?

Answer 2

L Main AC Bus

Question 3

If the L MAIN AC bus is unpowered, will the AUX TRU and ESS AC bus automatically switch to another power source? Which one?

Answer 3

Yes. Both switch to the R MAIN AC bus

Question 4

What is the purpose of the E-inverter?

Answer 4

Provides AC power for the ESS AC bus (if the ESS AC bus loses power)

Question 5

How long do you wait between selections of L ESS and R ESS when using HMG?

Answer 5

10 Secs

Question 6

If you lose L MAIN AC Bus, how would you power the L MAIN DC bus?

Answer 6

Depress the L TRU switch. Observe ‘RAC’ illuminate in the capsule

Question 7

What two power sources can power the ESS DC Bus simultaneously?

Answer 7

L/R Main batteries
AUX TRU (When powered by the HMG)

Question 8

When do the MAIN Battery switches illuminate?

Answer 8

1. When they are powering the ESS buses
2. When starting the APU
3. When AUX pump is operating.

Question 9

All automatic power transfers will be NBPTs except between…

Answer 9

External AC and APU power.

Question 10

What appears in the GEN switch capsule if the GEN FAILED?

Answer 10

Amber “OFF”

Question 11

The Ground service bus may be powered on the ground by:

Answer 11

1. R MAIN DC

2. R Batt or Ext DC when using one of the three Ground Service Bus switches.

Question 12

How can you tell if the Ground Service Bus is powered?

Answer 12

Beacon is on

Question 13

Can the Crew tell if the Ground service bus is on by looking at the cockpit electrical panel?

Answer 13

Yes. The GND SVC BUS capsule will have “ON” illuminated

Question 14

Is GND SVC BUS powered inflight? If so, by what?

Answer 14

Yes / R MAIN DC

Question 15

How many GND SVC BUS switches and where?

Answer 15

3

1. Fwd Ext Switch Panel
2. Tail Compartment.
3. Remote Refuel Panel

Question 16

When will the GND SVC BUS automatically shut off?

Answer 16

On the ground, with main door closed and forward external switch service panel AND tail compartment door are closed.

Question 17

What do the Avionics E-Batts power?

Answer 17

1. Clocks
2, 3. STBY INST Panel (SFD/EBDI)
4. Gear Handle and indicator
5,6. MCDU 1 and 3
7. CAPT Audio Panel

Question 18

Emer Batts when armed will activate…

Answer 18

when an ESS DC power drops below 20 Volts

Question 19

With E-Batts on, what appears on the MCDU 1 and MCDU 3?

Answer 19

MCDU 1 - STBY ENG INST and FUEL

MCDU 3 - BACK UP RADIOS (VHF 1 COM/NAV) and ATC

Question 20

When operating on E-Batts which comm can be tuned and how?

Answer 20

COM 1 / NAV 1 / ATC 1 on MCDU 3

Question 21

Can you plug in Ext AC and DC power simultaneously? Which has priority?

Answer 21

Yes.

AC has priority

Question 22

If you plug in Ext AC and DC simultaneously, AC will take priority and power the aircraft. If removed Ext AC power, will DC power automatically pick up the load?

Answer 22

No. You have to deselect Ext AC and reselect for DC Ext Power

Question 23

Why would you use DC EXT Power?

Answer 23

Start the APU with low battery voltage

Question 24

When should an open circuit breaker be reset?

Answer 24

If the affected component is required for safe flight and landing

Question 25

What is indicated if the R GEN switch displays an amber OFF light?

Answer 25

The GCU has tripped

Question 26

If both Generators are inop, which buses does the HMG power?

Answer 26

Both standby AC buses, both ESS DC busses, and the ESS AC bus

Question 27

What is the rating of the HMG?

Answer 27

10 kVA

Question 28

How is the HMG powered?

Answer 28

Left hyd system or PTU

Question 29

Selecting the L Bus tie switch to the ISLN position will:

Answer 29

Isolate the L MAIN AC bus from all power except the left IDG

Question 30

The minimum main battery voltage is:

Answer 30

22 volts

Question 31

Which battery is used to close the main door from the outside door switch?

Answer 31

Only the right battery, which is hard-wired to the main door electrical control circuit

Question 32

The function of the L-R MAIN TRU switch is:

Answer 32

The on-side MAIN AC BUS powers each main TRU. In the unlikely event that the on-side MAIN AC BUS should fail, the L-R MAIN TRU switch can be selected to the opposite side MAIN AC BUS to restore the TRU and its respective MAIN DC BUS.

Question 33

In what situation can TRU power more than one bus, which buses can it power?

Answer 33

When the HMG and left ESS/right ESS switches are IN/ON, the AUX TRU can power both essential DC buses.

Question 34

If the right main TRU fails, what should automatically power the right main DC bus?

Answer 34

the AUX TRU

Question 35

Which batteries are activated when the external battery switch is turned ON?

Answer 35

Both main batteries

Question 36

What item will be lost with only one AC power source operating in flight?

Answer 36

Galley power

Question 37

During an emergency evac or ditching after dark, how are emergency lights activated?

Answer 37

By selecting them ON with the emergency battery switch

Question 38

What will cause the 'cats eye' indicator to show white over black in the nav/strob lights?

Answer 38

If one or both strobe lights bulbs should fail

Question 39

Why are the NAV lights powered by two different power sources and what are they?

Answer 39

If the aircraft has to be towed, the NAV lights can be turned ON with battery power without having to start the APU. NAV LTS #1 = Left MAIN DC NAV LTS #2 = Left ESS DC

Question 40

If the landing light switches are left in during flight, when will the lights turn OFF automatically?

Answer 40

Passing through 18,000' (or they will change to "PULSE" mode if the pulse light switch is selected

Question 41

Will the taxi lights turn OFF automatically, if so, when?

Answer 41

Upon gear retraction

Question 42

How many emergency lighting batteries are installed?

Answer 42

Two

Question 43

During normal ops, the ground service bus receives power from...

Answer 43

R MAIN DC Bus

Question 44

From where can the E-Inverter receive power?

Answer 44

L or R ESS DC (Normally it receives power from L ESS DC if E inverter is required)

Question 45

How are the E-Batts charged?

Answer 45

L Instrument E-Batt - L STBY AC Bus R Instrument E-Batt - R STBY AC Bus Forward Lighting E-Batt - L MAIN AC Aft Lighting E-Batt- R MAIN AC

Question 46

What items are capable of being powered by the battery tie bus?

Answer 46

Aux Pump APU Starter ESS DC Buses

Question 47

How many TRUs are normally operating in flight?

Answer 47

Four, the AUX TRU is in standby mode, available to pick up any, single TRU

Question 48

If the Ground Service Bus is selected on with no power on the aircraft, what will power it?

Answer 48

Right Main Battery

Question 49

Which batteries are activated when the external battery switch is turned on?

Answer 49

Both main batteries

Question 50

In Flight, how is the ground service bus normally powered?

Answer 50

R MAIN DC

Question 51

Whenever the GND SVC BUS is turned on, what light illuminates?

Answer 51

Lower beacon

Question 52

Which buses are powered with only external DC connected?

Answer 52

L - R ESS and MAIN DC GND SVC Bus ESS AC (Phase A only - powered thru the E-Inverter)

Question 53

What electrical components are under the forward floor?

Answer 53

TRUs and E-Inverter

Question 54

How many TRUs are on the aircraft?

Answer 54

7 5 (L/R MAIN & ESS and AUX) 2 - Battery chargers

Question 55

How many Circuit Panels are there?

Answer 55

``` 7 POP CPOP LEER L PDB REER - 2 R PDB ```

Question 56

Which BPCU (Bus power control unit) controls break power transfer control?

Answer 56

Left BPCU