Electrical Flashcards
What supplies AC power is available to the a/c?
Two IDGs, APU generator, external power
What happens when external power is selected on?
It disconnects all Engine and APU power from buses and uses external power
What components make up an IDG?
Generator and CSD or Constant Speed Drive
DRIVE light illuminates under what conditions?
High IDG oil temp or Low IDG oil pressure
Whats the priority of the IDG for each engine?
It has the highest priority over any other power source
What does the L and R Gen Cont switch move?
Connects or disconnects the Gen Cont switch breaker
Does the APU generator has a CSD?
No, relatively constant speed
When does the APU Gen Off message illuminate?
The APU is operating, and the apu generator control breaker is open beacuse of a fault or the apu gen switched is selected off
Ground handling bus can only be powered by what sources of power?
External or Apu power
What are the indications that galley buses have shed?
No indication
What is the bus tie system function?
Provide power to both main ac and dc busses and isolate faults.
What is the load shedding sequence?
Galley busses, utility busses and inidividual equipent items powered by the main ac busses.
When is the utility bus off light illuminated, along with the utility and galley bus are un-powered?
Both thrust levers are advanced on the ground with a single power source. Electrical overload. Single Generator Operations in-flight. Engine Start with apu providing electrical power.
What pump can be shed if APU or external power is the only power source?
C ELEC HYD 2
What is the shed sequence during start?
Left engine start - L/R utility and galley buses shed. Right engine start- only R utility and galley bus shed.
How long does the battery power the a/c?
30 min
When is the hot batt bus powered?
All the time, even if batt is in off position.
What is powered when batt is on and in standby power?
batt bus, standby busses
Describe the STBY Power selector?
Off - standby busses are not powered. Auto- provides automatic stby bus transfer to battery power if AC power is lost. Bat- standby busses are powered from the main battery . Off annunciation - either the AC or DC standby bus is not powered
What bus are the flight instruments powered by?
L and R main AC busses respectively.
-300 how much standby power do you get if loss of power?
90 min, main batt and apu batt are paralleled.
-300 the HDG or Hydraulic Driven Generator activates automatically when…
The L and R main AC busses are unpowered
How long is standby power available on 767-300
30 min, and if battery power is depleted the flaps and gear cannot be extended
767ER when does the HDG activate?
When the L and R main AC busses are unpowered. its driven by the center hydraulic system
