Electrical

Question 1

How are AC Buses 1 and 2 powered during normal ops

Answer 1

1) Respective Engine Generator (IDG 1 or 2)
2) External Power
3) APU generator

Question 2

How can the AC ESS Bus be powered

Answer 2

1) AC Bus 1
2) AC Bus 2 manually, when AC ESS FEED pb is selected to ALTN
3) AC Bus 2 automatically via system logic

Question 3

Describe the electrical system’s power priority

Answer 3

1) Respective Engine Gen
2) External Power (If selected ON)
3) APU Gen
4) Opposite Engine Gen.

Question 4

What are the functions of the BUS TIE pb

Answer 4

AUTO (Light Out) - Power priority order logic is active

OFF - Power priority order logic is de-activated and

1) AC Bus 1 and 2 can only be powered by their respective engine generator

2) External or APU power cannot be applied to the aircraft

Question 5

What is the purpose of the AC ESS FEED pb

Answer 5

Manually command AC Bus 2 to power the AC ESS Bus

Question 6

When the AC ESS FEED pb is in the “Light Out” configuration, what is happening? What happens if AC BUS 1 Fails

Answer 6

1) AC Bus 1 powers the AC ESS BUS - Normal Configuration

2) Should AC Bus 1 fail, AC Bus 2 automatically powers the AC ESS BUS

Question 7

When the AC ESS FEED pb is in the ALTN configuration, what is happening?

Answer 7

1) AC Bus 2 is commanded to power AC ESS Bus regardless of the status of the AC BUS 1

2) ALTN appears only when the pb is selected

Question 8

What information is provided by ECAM ELEC page for GEN 1 and 2 and the APU generator

Answer 8

1) % of output
2) Voltage
3) Frequency

Question 9

What information is provided by the ECAM ELEC page for EXT POWER

Answer 9

1) Voltage
2) Frequency

Question 10

When will the EXT PWR legend appear on the ECAM ELEC page?

Answer 10

External power is connected to the aircraft and Volt and Freqs. meet requirements

Question 11

When will the word SHED appear under the AC ESS or DC ESS buses

Answer 11

When the respective SHED bus has automatically shed.

Question 12

When does the GALLEY SHED display on the ECAM ELEC page?

Answer 12

1) In-Flight- When on single gen power the main bus is automatically depowered, however secondary bus remains powered

2) Ground - When either external or APU power is in use, both main and secondary galley buses remain powered

3) Galley pb OFF - GALLEY SHED Indicates that the galleys main and secondary buses are depowered

Question 13

In order to avoid damage, what should you NOT do with regard to the IDG 1 and 2 pbs

Answer 13

1) Do not disconnect unless the engine is operating or windmilling

2) Do Not Hold the pb(s) for more than 3 seconds

Question 14

How are the circuit breakers color coded?

Answer 14

1) Green
- The CB is monitored by the Flight Warning Computers (FWCs)
- C/B TRIPPED message on ECAM if CB is open for more than 1 minute

2) Black
- CB is not monitored by FWC so no ECAM message for C/B TRIPPED
- The system which the CB supports may be monitored by FWC so may get another ECAM message

3) Yellow - Pulled when flying on batteries only

4) Red Cap
- Prevents CB from being reset
- Provides circuit protection to the Wing Tip Breakers (WTB)

Question 15

How is Gen 1 affected when the GEN 1 LINE pb is selected OFF

Answer 15

1) Opens Gen 1 line contactor isolating it from the remainder of the electrical system

2) Gen 1 is limited to only powering 1 fuel pump in each wing tank

Question 16

Describe the two methods of activating the emergency Generator

Answer 16

1) Automatically with loss of power to AC Bus 1 and 2 in flight will deploy the RAT and activate the Emer Gen.

2) Manually - by selecting the MAN ON pb deploys the RAT and Emer Gen

Question 17

What will selecting the RAT MAN On pb on the Hyd panel do?

Answer 17

Deploy the RAT but NOT activate the Emer Gen.

Question 18

What does “Emergency Generation After Loss of All Main Generators” mean

Answer 18

The aircraft is in an Electrical Emergency (ELEC EMER CONFIG displayed on ECAM). AC buses 1 and 2 are unpowered and the Emergency Gen is powering:

1) AC Ess Bus
2) DC Ess Bus through the ESS TR
3) AC and DC ESS SHED buses through their ESS buses

Question 19

What happens to the Emer Gen when the LDG Gear is lowered

Answer 19

It is automatically de-activated and the aircraft batteries become the sole source of electrical power

Question 20

When will you get a red FAULT light on the EMER ELEC PWR panel

Answer 20

AC buses 1 and 2 are unpowered AND the RAT is deployed but the Emer Gen is not supplying power

Question 21

Where is the MAINT BUS switch located, what happens when you turn it on and what kind of power source does it need?

Answer 21

1) Located on the electrical panel on the ceiling of the fwd galley

2) When you turn it on it allows external power for ground servicing without having to energise the entire aircrafts electrical system

3) Only needs external power to be connected and have good volt and freqs.

Question 22

With the engines not running, what power source has priority with the APU and External Power connected

Answer 22

External Power

Question 23

if the APU AVAIL light is on what does this indicate

Answer 23

APU is “On Speed”

Question 24

If the ON light on the EXT PWR pb is illuminated, what does this indicate

Answer 24

External Power has been selected