3.4

Question 1

What is the primary source of internal electrical power

And the secondary

Answer 1

-onboard engine drivenGenerators or apus
Ac batteries are the secondary source of onboard electrical power and are usually considered as a last resort to start APU or an Ac engine only when ground power is not avalaible

Question 2

What do dc current generators do

Answer 2

Transform engine mechanical energy into electrical energy to power Ac electrical loads and charge Ac batteries

Question 3

What is an apu

Answer 3

Self contained gas turbine engines that produce energy for functions other than propulsion. Provides power to start the main engine.

Question 4

Ac apus produce what amount of current

Answer 4

115 volts alternating current at 400hertz to run onboard electrical systems

Question 5

Primary purpose of batteries

Answer 5

Source of electrical power providing priority to emergency circuits in the event of electrical power failure

Question 6

What are external ground power supplies used for

Answer 6

Starting Ac engines
Provision of the electrical needs of an Ac during servicing

This saves the Ac batteries or the need to run Ac engines or alternative power units to supply adequate electrical power

Question 7

Information on a ground power socket

And he symbol

Answer 7

External power connection point

What it’s used for eg servicing and starting

Voltages and cycled as appropriate eg 115vac 400hz and 28vdc

Symbol - “E” with a short bottom

Question 8

Symbol for alternating current

Standard nato symbol for dc power source eg batteries

Answer 8

Tilted dollar sign

Checkered diamond shape on side

Question 9

Two main categories of gpu

Answer 9

Engine driven gpus

Hanger mains driver gpus (tru)

Question 10

Requirements relating to the operations of gse around Ac must what

Answer 10

Be adhered to by all operators of gse

Question 11

Types of hanger (mains) driven gpus

Answer 11

Tru

Triectrons

Question 12

A battery cart is used to power what

Answer 12

A low voltage dc supply is needed

Can be used for engine starts

Question 13

Positioning of gpus must be

Engine driven
Mains

Answer 13

Engine driven-produce unwanted gas and fumes that shouldn’t be placed downwind from air conditioning inlet vents
Mains-should remain indoors and not cross over hanger door guide rails without protection

Question 14

Lead cables and plugs should be

Answer 14

Fully unwound
- not coiled/crossed. “S” formation

Condition checked
-worn, nicks, insulation compromised and exposed conductors

Protected

Question 15

Warning Abouts gpus and bonding leads

Answer 15

Don’t attach bonding leads to or otherwise earth, gpus

Question 16

Warning about mains powered gpu and unprotected main powered gse

Answer 16

Don’t use mains powered gpu outside hanger or in damp conditions
Don’t use unprotected mains powered gse with a mains powered gpu

Question 17

Procedure for following mains powered gpus

Answer 17

Remove and stow the Ac earthing lead prior to connecting mains power to receptacle
Ensure other gse bonded to Ac isn’t earthed
Reconnect Ac earthing lead after disconnecting gpu Power cable from Ac

Question 18

Thermal runaway is in what kind of battery

Answer 18

Nicad

Question 19

I’d smoke or fumes are seen coming from the battery compartment or or overheating is suspected, do what

Answer 19

switch battery off
Terminate all types of servicing and evacuate people to safe area ASAP
Have fire extinguishers and personel positioned at a safe distance
Report to ncoic servicing
Allow at least 60mins for batteries to cool before approaching Ac
Don’t reapply Power
Remove battery only when cooled sufficiently

Question 20

Purpose of isolating electrical power

Answer 20

Ensure the Ac is electrically safe for pers to work on

Question 21

Occasions when you would isolate electrical power

Answer 21

Ac cleaning 
Solvent cleaning
Lox/gox replenishment 
Open fuel systems or Ac tanks
Weapons loading
Disconnection of components which May contain volatile fluids
Disconnection/connection of avionic

Question 22

Full Ac isolation is required when

Answer 22

There is any risk that the tradesperson maybe exposed to live conductors

Question 23

Onboard system isolation

Answer 23

Snco ic Ac 
700/cmms work order
State board updated 
Master battery off 
Dummy the fuses 
CBS pulled 
Placards

Question 24

System safety devices for Ac electrical power isolation

Answer 24

Cb lockout
Dummy fuse
Dummy plug
Placards

Question 25

Ac Power isolation procedure

Answer 25

Snco is Ac 
Consult other trades
700/cmms
State board
Master battery-off 
Placards fitted in flight deck
Disconnect and stow battery leads 
Battery dummy plug and warning sign in battery compartment
Remove external ground power supply 
Fit dummy plu, warning sign in power receptacle