Electrical System Flashcards
What is the function of the Standby Battery?
Powers the Hot Busbar and provides power to initialise the EPCU. The Hot busbar powers the Extinguisher squibs, boarding lights and dome lights.
What is the function of the Avionics Battery Bus?
Powers the emergency standby radio, Integrated Standby Instrument (ISI), Storm lights and Standby Compass Light
Where do the engine driven DC Generators supply power directly to:
L and R Main Feeder Bus respectively
When are the Main Busbars normally tied?
Automatically by the ECPU when GPU/APU power connected and for engine starting
If both AC generators fail in flight, how can the Secondary Busbars be powered?
Vertically tied to each respective Main Feeder Bus
With the engines shut down on the ground, how can the AC services be powered?
AC external power connected via a on the inboard RH
What systems can be powered by an AC GPU?
All services
What does the moving the Batt Master Switch to ON achieve?
Connects the Main Battery, Aux and Standby to the Essential Busbars.
Where is the DC GPU Connection Socket located?
Left side of the nose
What does a reading of +1.2 mean on a Battery Load Indication?
Battery has exceeded max load of +1.0 (overload)
When would a Battery Temperature Readout be Amber?
50-65C
If the aircraft is being powered from a DC GPU, how is this indicated?
Top left of the ELEC SYS page - reads DC EXT PWR ON
Where on the flight deck are the Avionics CBs located?
Top left behind the captain’s seat
What is the effect of switching on the Standby Battery Switch?
Connects the Standby battery to the left Main feeder bus but does not power it
How is the Electrical System protected from GPU/APU over-voltage?
Generator control units on both disconnect GPU/APU
What is the correct sequence for applying DC GPU Power to a “cold” aircraft?
Master Battery On, Aux switches on, GPU power connected, EXT PWR ON
What will prevent the APU Generator from coming on line?
Selecting EXT PWR switch to ON before switching on the APU Gen.
In a fully powered electrical system, what is the Bus Tie Configuration?
Disconnected
What would happen to the DC Generators were to fail in flight?
TRUs will power whole system through L+R Bus Tie Contacters
What is the minimum Busbar Voltage for a engine start using GPU or APU?
26 v DC minimum
What is the minimum Battery Temperature for take off?
-20C
How can a BATT HOT Warning be confirmed?
Select ELEC SYS page
What does a BATTERY Caution indicate?
The associated battery is not connected to the Main Bus for charging.
What power supplies are available if the EPCU reverts to emergency Mode?
Essential Busbars, Main and Auxiliary batteries if required for engine start.
