8/9/2019 Electrical Systems2

1/16

Aircraft Electrical Systems

By Jake Heindselman

8/9/2019 Electrical Systems2

2/16

Electricity A form of energy associated with stationary ormoving electrons, ions, or other charged particles

Electricity provides electricalpower throughout the aircraft

8/9/2019 Electrical Systems2

3/16

Sources, Switches, and Wiring Circuits

Battery

Alternator/Generator

Circuit breakers/Fuses

Voltage regulator

Ammeter

Master switch

Electrical System

8/9/2019 Electrical Systems2

4/16

Battery

Stores electrical energy

Provides electrical power to

start the engine

Stores a limited supply of

backup power if alternator or

generator fails

Recharges when engine is

running (turning Alt/Gen)

8/9/2019 Electrical Systems2

5/16

AlternatorProduces alternating current(AC) which is converted to

direct current (DC)

Belt driven (engine-driven)Recharges battery whileengine is running

Creates sufficient current tooperate entire electricalsystem, even at low EngineR.P.M.

Electrical current is moreconstant throughout differentengine speeds than agenerator

8/9/2019 Electrical Systems2

6/16

Generator

Produces direct currentelectrical charge (DC)

Belt driven by theengine

Doesnt produceenough current at lowR.P.M. to operate entireelectrical system

Aircraft with generators

use battery power at lowengine R.P.M.

8/9/2019 Electrical Systems2

7/16

Magneto Self contained ignition

unit that provides pulsesof electricity to the twospark plugs

Used in internalcombustion ignitionengines

Doesnt require a

battery to function

Each spark plug has aseparate magneto system

Converts mechanicalenergy to electricalenergy

8/9/2019 Electrical Systems2

8/16

Spark Plugs

Receives sparkelectricity from magneto

Ignites compressedfuel/air mixture insideengine cylinder

Aircraft engines have twospark plugs (two magnetosystems) per cylinder

Electricity travels frommagneto to magneto sparkplug in heavily insulatedwires HIGH VOLTAGE

8/9/2019 Electrical Systems2

9/16

Circuit Breaker/Fuses

Protects the electrical systemfrom electrical overload

Overload can cause damage to

components in the electrical

system

Fuses have an internal metal

wire or strip that melts when too

much electrical current flows

through it

Circuit breakers have a switch

that trips if too much electrical

current flows through it

The switch can be manually

reset instead of replacing it

8/9/2019 Electrical Systems2

10/16

Voltage Regulator

Controls the rate of

charge to the battery

Stabilizes the generator

or alternator electricaloutput

Compares thegenerator/alternatorvoltage output to the

battery voltage

8/9/2019 Electrical Systems2

11/16

Ammeter Monitors the performance ofthe electrical system

Shows if thealternator/generator isproducing an adequate supply

of electrical power

Indicates whether or not thebattery receives an electricalcharge

Not all airplanes are equippedwith an ammeter

Some airplanes have awarning light to alert the pilot ofan electrical system problem

8/9/2019 Electrical Systems2

12/16

Master SwitchTurns Electric system on or off

Controls entire electrical systemexcept for Magneto Ignitionsystem, including

interior/exterior lights,

radios, fuel gauges, pumps, - and engine starter motor

Some airplanes equipped withbattery switch and alternatorswitch (split switch)

Alternator switch (ALT)disconnects alternator fromelectrical system in case ofalternator failure (ALT=OFF)

8/9/2019 Electrical Systems2

13/16

Ground Power Unit (GPU)

Provides aircraftwith power fromexternal power supply

Very useful forstarting engine in cold

weather

Some GPUs built

into airport jet-ways toreduce wear on a/csystems and toprovide immediatepower for ground ops

8/9/2019 Electrical Systems2

14/16

SummaryComponents

Battery Alternator/Generator Magneto Spark Plugs Fuses/Circuit Breaker Voltage Regulator

Controls/ Tools

Master Switch

Alternator Switch Ammeter Ground Power Unit (GPU)

8/9/2019 Electrical Systems2

15/16

References

Wikipedia, (2009), http://en.wikipedia.org/wiki/Electricity, 2-1-2009

Aeronautical Knowledge Handbook, (2009),http://ma3naido.blogspot.com/2007/11/aircraft-electrical-system.html , 2-1-2009

Wikipedia, (2009), http://en.wikipedia.org/wiki/Fuse_(electrical), 2-1-2009

Aircraft Technical, (2009),http://www.pilotfriend.com/training/flight_training/tech/elec.htm , 2-2-2009

http://en.wikipedia.org/wiki/Electricityhttp://ma3naido.blogspot.com/2007/11/aircraft-electrical-system.htmlhttp://en.wikipedia.org/wiki/Fuse_(electrical)http://www.pilotfriend.com/training/flight_training/tech/elec.htmhttp://www.pilotfriend.com/training/flight_training/tech/elec.htmhttp://en.wikipedia.org/wiki/Fuse_(electrical)http://ma3naido.blogspot.com/2007/11/aircraft-electrical-system.htmlhttp://ma3naido.blogspot.com/2007/11/aircraft-electrical-system.htmlhttp://ma3naido.blogspot.com/2007/11/aircraft-electrical-system.htmlhttp://ma3naido.blogspot.com/2007/11/aircraft-electrical-system.htmlhttp://ma3naido.blogspot.com/2007/11/aircraft-electrical-system.htmlhttp://en.wikipedia.org/wiki/Electricity

8/9/2019 Electrical Systems2

16/16

The End