Electrical Questions Flashcards
(11 cards)
Explain the sources of electrical generation and their sources
Generator located with each engine. APU Generator can also supply entire system. Generator 1 supplies AC BUS 1 and generator 2 supplies AC BUS 2. One engine generator can supply entire system. External power supplies entire system also.
Inflight, under normal ops, which generator has the highest load and why?
Generator 1 has the higher load due to running the AC ESS BUS under normal operations.
What does the emergency generator power?
Emergency Generator supplies the AC ESS BUS and the DC ESS BUS via the ESS TR.
How long does it take for the EMER GEN to come online? During this time, what is powering the A/C? What is powered with this and what would you see in the flight deck?
Emergency generator takes approximately 8 seconds to come online. During this time A/C is powered by batteries only. With emergency generator online, PFD 1/ND1/FMGC1/RMP 1/VOR & ILS 1/DME 1/VHF 1/ATC 1 usable.
What is the purpose of the Generator 1 line push button?
Allows the pump 1 in each wing rank to still be energised and prevent a gravity feeding situation by isolating the entire generator. Opens the generator 1 line contactor but fuel pump remains connected. SMOKE light comes on when smoke detected in avionics ventilation duct.
Approximately, what speed must be maintained to prevent the RAT from stalling?
The minimum approach speed must be at least 140kts to prevent the RAT from stalling.
What is the difference between selecting the IDG off as opposed to the Generator off?
Pressing the IDG disconnect button removes the IDG from its driveshaft. Can only be reset on the ground with the engine off. Pushing the generator PB off, de-energises the generator field and the line contactor opens.
What is the purpose of selecting the APU master switch ON in the smoke configuration checklist?
In EMER ELEC CONFIG, switching the APU MASTER ON, the battery contactors will automatically close for a max of 3 mins. Enables the flight crew to manually control the outflow valve that is powered by the DC BAT BUS.
Under what circumstances will the RAT deploy automatically?
Upon the loss of the main generators resulting in AC BUS 1 & AC BUS 2 being without power.
At what altitude can the APU be started in the EMER ELEC CONFIG and why?
25000ft. Cannot be started on batteries alone above this altitude. Air being thinner, less likelihood of APU actually starting and unnecessarily draining the limited supply that the batteries have.
In flight under normal ops, what altitude can the APU supply elec and/or bleed demand?
The APU can provide electrical power across the entire flight envelope. It can provide bleed air and elec power between 22,500ft to -2,000ft. Single pack 22,500ft and dual packs 15,000ft
