Unit 1-12 Flashcards
What are the three common AC power distribution systems?
Parallel bus
Split bus
Split-Parallel bus
Describe parallel bus systems*
Is the APU flight operable?*
Electrical load equally shared by all working generators
All generators are connected to a single sync bus during operation
APU not flight operable (no back up)
Describe split bus systems*
Is the APU flight operable?*
Each generator powers one main AC bus at a time
If one generator fails another is available as back-up by closing breakers
APUs are operational in flight
If the main generators fail, what would supply the AC power?
If that fails?
APU generator
RAT would be used to drive an emergency power generator
What is the RAT?*
Ram Air Turbine
Small turbine that supplies an AC backup power source if all engines are lost
What is the most critical AC power source?*
What does it do?
Describe it*
Static inverter
Change DC to AC
Powered by the ship’s batteries to produce AC power when all other systems failed
Solid state device
What is the SSB?*
What does it do?*
What aircraft is it found on?*
Split Systems Breaker (SSB)
Connects the left and right-side busses/generators
SSB closed is like a parallel bus system
SSB open is like a split bus system
B747
Split-parallel
What is the most electric airplane?
Boeing 787
On the 787 what systems have been replaced by electrical systems?*
Starter generator
Transformer rectifier
Hydraulic pump
Motor
Nitrogen Generation System
What does the nitrogen generator do?*
Generates nitrogen or nitrogen-rich air to help avoid flammability of the void above jet fuel in fuel tanks
Pumps ozone into the fuel takes to eliminate the oxygen (flammable) and increase the nitrogen
Electrically powered device that kills oxygen (flammable) in the fuel tank to make room for nitrogen
