Electrical System

Question 1

What is the function of the Standby Battery?

Answer 1

Powers the Hot Busbar and provides power to initialise the EPCU. The Hot busbar powers the Extinguisher squibs, boarding lights and dome lights.

Question 2

What is the function of the Avionics Battery Bus?

Answer 2

Powers the emergency standby radio, Integrated Standby Instrument (ISI), Storm lights and Standby Compass Light

Question 3

Where do the engine driven DC Generators supply power directly to:

Answer 3

L and R Main Feeder Bus respectively

Question 4

When are the Main Busbars normally tied?

Answer 4

Automatically by the ECPU when GPU/APU power connected and for engine starting

Question 5

If both AC generators fail in flight, how can the Secondary Busbars be powered?

Answer 5

Vertically tied to each respective Main Feeder Bus

Question 6

With the engines shut down on the ground, how can the AC services be powered?

Answer 6

AC external power connected via a on the inboard RH

Question 7

What systems can be powered by an AC GPU?

Answer 7

All services

Question 8

What does the moving the Batt Master Switch to ON achieve?

Answer 8

Connects the Main Battery, Aux and Standby to the Essential Busbars.

Question 9

Where is the DC GPU Connection Socket located?

Answer 9

Left side of the nose

Question 10

What does a reading of +1.2 mean on a Battery Load Indication?

Answer 10

Battery has exceeded max load of +1.0 (overload)

Question 11

When would a Battery Temperature Readout be Amber?

Answer 11

50-65C

Question 12

If the aircraft is being powered from a DC GPU, how is this indicated?

Answer 12

Top left of the ELEC SYS page - reads DC EXT PWR ON

Question 13

Where on the flight deck are the Avionics CBs located?

Answer 13

Top left behind the captain’s seat

Question 14

What is the effect of switching on the Standby Battery Switch?

Answer 14

Connects the Standby battery to the left Main feeder bus but does not power it

Question 15

How is the Electrical System protected from GPU/APU over-voltage?

Answer 15

Generator control units on both disconnect GPU/APU

Question 16

What is the correct sequence for applying DC GPU Power to a “cold” aircraft?

Answer 16

Master Battery On, Aux switches on, GPU power connected, EXT PWR ON

Question 17

What will prevent the APU Generator from coming on line?

Answer 17

Selecting EXT PWR switch to ON before switching on the APU Gen.

Question 18

In a fully powered electrical system, what is the Bus Tie Configuration?

Answer 18

Disconnected

Question 19

What would happen to the DC Generators were to fail in flight?

Answer 19

TRUs will power whole system through L+R Bus Tie Contacters

Question 20

What is the minimum Busbar Voltage for a engine start using GPU or APU?

Answer 20

26 v DC minimum

Question 21

What is the minimum Battery Temperature for take off?

Answer 21

-20C

Question 22

How can a BATT HOT Warning be confirmed?

Answer 22

Select ELEC SYS page

Question 23

What does a BATTERY Caution indicate?

Answer 23

The associated battery is not connected to the Main Bus for charging.

Question 24

What power supplies are available if the EPCU reverts to emergency Mode?

Answer 24

Essential Busbars, Main and Auxiliary batteries if required for engine start.

Question 25

If Battery Essential Services Only is selected, what Flight Instruments are available?

Answer 25

ADC 1, AHRS 1 and 2, COMM 1, NAV 1, ISI, ED.

Question 26

What is the Battery Duration if operating on Battery Essential Services in flight?

Answer 26

45 minutes

Question 27

Which systems are powered by the Avionics Battery Bus?

Answer 27

Standby Emergency Radio, ISI (Integrated Standby Instrument), Storm Lights, Standby Compass Light