24 Electrical

Question 1

What voltage does the DC system operate to?

Answer 1

28V DC

Question 2

What does the GALY and CAB pb control?

Answer 2

Power to the main and secondary galley

Question 3

What frequency does the AC system operate to?

Answer 3

400Hz

Question 4

What voltage does the AC system operate to?

Answer 4

115/200V AC

Question 5

How much power is generated by the generators?

Answer 5

90 KVA

Question 6

How many phase is the electric supply?

Answer 6

3 phase

Question 7

When does the IDG temperature on the ELEC SD page turn amber?

Answer 7

Above 185 degC

Question 8

What does the commercial pb control?

Answer 8

Commercial electric loads:

• Cabin and cargo lights
• Water and toilet system
• Drain mast ice protection
• Galleys

Question 9

What does the GEN 1 LINE pb do?

Answer 9

Isolates GEN 1 from AC BUS 1

The number 1 fuel pumps in both inner tanks are now connected directly to GEN 1 (normally to AC BUS 1)

Used for smoke drill, sourcing smoke

Question 10

When does the IDG temperature generate an advisory?

Answer 10

Above 147 degC

Question 11

Approximately how long after APU shut down does it take for the APU intake flap to fully close?

Answer 11

2 minutes

Question 12

What is the power of the emergency generator?

Answer 12

5 KVA

Question 13

What are the tolerances for amber values on the generators? (Load/Voltage/Frequency)

Answer 13

Amber when:
>100% load
>120V or <110V voltage
>410Hz or <390Hz frequency

Question 14

When do the battery DC voltage and current indications on the ELEC SD page turn amber?

Answer 14

> 31V or <25V

>5A

Question 15

When are the main galleys shed?

Answer 15

When only one generator is operating in flight

or on the ground when the aircraft is being supplied by 1 engine generator only

Question 16

After the loss of AC BUS 1 and 2, how long does it take for RAT extension and emergency generator coupling?

Answer 16

8 seconds

Question 17

What restrictions are there on the operation of the red guarded IDG pb?

Answer 17

Do not press for more than 3 seconds as it may damage the disconnect mechanism. The IDG should only be disconnected on a running or windmilling engine.

Question 18

What happens if AC BUS 1 and 2 are lost simultaneously?

Answer 18

Emergency Electrical Configuration

If the aircraft speed is over 100 knots:

• RAT extends
• Emer gen driven by blue hydraulic system
• Emer gen connects to electrical network once operational (within tolerances)

Question 19

What is the AC ESS FEED pb used for?

Answer 19

If AC BUS 1 is lost, then the AC ESS and DC ESS (via TR1) are also lost. AC ESS FEED allows AC BUS 2 to power the AC ESS BUS, and subsequently DC ESS BUS via the ESS TR.

This procedure is shown on ECAM during the AC ESS BUS FAULT

Question 20

Which screens are lost in an AC BUS 1 FAULT?

Answer 20

Captain PFD, ND and EWD (Upper DU)

Question 21

Which screens are lost in an AC BUS 2 FAULT?

Answer 21

FO PFD, ND and SD (Lower DU)

Question 22

Which screens are lost in EMER ELEC?

Answer 22

FO PFD, ND and SD (Lower DU)

Question 23

What is the normal configuration of the electrical system?

Answer 23

GEN 1 supplies AC BUS 1, which supplies AC ESS BUS and TR 1. This supplies DC BUS 1 , which supplies DC BAT BUS and DC ESS BUS.

GEN 2 supplies AC BUS 2, which supplies TR 2. This supplies DC BUS 2.

The two batteries are connected to the DC BAT BUS, and will be disconnected by the BCL when fully charged.

Question 24

What is the reconfiguration of the electrical system in an AC BUS 1 fault?

Answer 24

AC BUS 1 is no longer supplied, which leaves the AC ESS BUS, TR 1, and subsequently DC BUS 1, DC BAT BUS, and DC ESS BUS without power.

In this situation, the AC ESS FEED pb can be pressed, to supply AC ESS BUS from AC BUS 2. AC ESS BUS then supplies the ESS TR, which supplies the DC ESS BUS.

DC BUS 2 supplies DC BUS 1 and DC BAT BUS automatically after 5 seconds

Question 25

What is the reconfiguration of the electrical system in a single TR fault?

Answer 25

The ESS TR automatically replaces the faulty one through the AC ESS BUS, and powers the DC ESS BUS. DC BUS 2 powers the DC BAT BUS and DC BUS 1 (in a TR1 fault)

Question 26

What is the reconfiguration of the electrical system in a double TR fault?

Answer 26

The ESS TR powers the DC ESS BUS from the AC ESS BUS. As both TRs are lost; DC BUS 1, DC BUS 2, and the DC BAT BUS are lost.

Question 27

What is the difference between emergency electrical configuration (loss of both generators) and the smoke configuration?

Answer 27

They are the same, except in the smoke configuration the number 1 fuel pumps in both inner tanks are connected upstream of the GEN 1 line connector (i.e. directly to GEN 1)

Question 28

What is the configuration of the electrical system in emergency electrical configuration in flight?

Answer 28

The EMER GEN (RAT, blue hydraulic system) supplies the AC ESS BUS, and the ESS TR. This supplies the DC ESS BUS.

Question 29

What is the configuration of the electrical system in emergency electrical configuration if the RAT stalls or on the ground below 100 kts?

Answer 29

The EMER GEN has nothing to drive it. The batteries supply the electrical system via the static inverter. AC SHED ESS BUS and DC SHED ESS BUS are lost.

Question 30

What happens below 50 kts on the ground in the emergency electrical configuration?

Answer 30

The AC ESS BUS is automatically shed, leading to the loss of all DUs.