Electrical Flashcards
In normal operations, the electrical system is divided into _____ networks.
2
Power to the DC system is supplied by:
4 Eng. driven DC Generators (28Vdc, 400A)
1 APU driven DC Starter/Generator (28Vdc, 400A)
2 NiCad Main Batteries, 24V 44ah
1 Lead Acid Backup Battery, 24v 5ah
1 GPU Connection 1600a rating
Electrical system management and protection is performed by:
Electronic Distribution Logic (EDL)
Generator Control Units (GCU)
The ______ has priority over al other power sources.
GPU
Generators _____ and _____ supply the left electrical network
1
3
Generators _____ and ______ supply the right electrical network.
2
4
The APU is normally connected in parallel to generators _______ and ______.
2
4
The APU generator can replace any inoperative _________ or may be used before engine starting.
Generator
Both main batteries are _______ Vdc _______ amp hour NiCads
24
44
The batteries cannot be recharged by the __________.
GPU
The No. 1 battery is charged by the generators connected to _____ during normal flight operations
the left network
The _____ battery provides electrical power for APU starting
2
When on the ground with the batteries as the only electrical power source the ________ busses are deenergized.
Shed
During APU starting, the _____ battery is isolated from the load busses.
1
The batteries can provide ____ minutes of power in an electrical emergency.
40
An electrical emergency is defined as:
a loss of all generators
In an electrical emergency, EDL automatically configures the system dedicating the batteries to the ___________ and ________ busses only
essential
central
If the automatic transfer fails, you can manually connect the batteries to the essential busses by pressing the __________ button
essential power
On the ground, all DC busses can be energized if at least one of the following conditions is met:
GPU in use
1 Generator online & shed bus switch selected to OVRD
3 Generators online
The _____ ________ bus is energized by connecting the GPU to the airplane with the batteries off and the GPC, BC1 and BC2 open
ground service
A “BATT OVTEMP” warning message is presented on the EICAS when the associated battery temperature exceeds ______ ºC.
70
A ____ Vdc, ___ Ah, sealed _____ _____ backup battery provides stabilized power for operation of the _______ protective function, even in case of a short circuit when system voltage may drop to near 0 volts.
24
5
lead acid
GCU
For the backup battery to be charged the system must be energized through a power source other than external power and a ________ selector must be set to AUTO
battery
The primary power source for the aircraft is the four 28 Vdc brushless ______ ______ _______.
Engine Driven Generators
The aircraft generators will come online when engine speed reaches _________ N2
56.4%
A “GEN 1(2,3,4) OVLD” caution message indicated that the associated generator is above _______ amps.
400
If an over voltage is detected, the associated _______ isolates the generator from the DC bus.
GCU
A generator reset attempt is allowed ______ time(s) after a failure.
1
The APU and GPU are connected to the aircraft electrical system through the __________ DC bus which also provides ________ sharing in the event of generator failure or engine shutdown.
Central
Load
The ______ starter generator can replace any engine dirven generator.
APU
The APU generator supplies electrical power to the system at _____ % RPM plus ______ seconds
95
7
If the airplane is on the ground, all DC busses will be kept energized for which of the following:
GPU on and connected: 4 Generators online: 3 Generators online: 2 Generators online: 1 Generator online: At least 1 Generator online with Shed Bus set to "OVRD":
Yes Yes Yes No No Yes
If the airplane is in the air, all DC busses will be kept energized if at least ______ generators are online.
3
All generator currents and voltage can be monitored on the ______ page of the _______.
Electric
MFD
The following lights are powered by the Ground Service Bus:
_________ __________
_________ __________
_________ __________
Pax Cabin Lights Lav Lights
Galley Lights Courtesy/Stair Lights
Cockpit Dome Lights Baggage/Service Compartment Lights
The AC system is powered by ____ 250Vac single phase static _______ (NA after Legacy s/n 863)
1
inverter
Avionics Master push buttons allow disconnection of some navigation and communication equipment from the load busses while starting the ______ on the ground.
APU
The maximum load on the engine generator is ______ amps.
400
The maximum load on the APU starter-generator up to 30,000 ft is _________ amps. The maximum load above 30,000 ft is _____ amps.
400
300
The minimum battery temperature for APU start is ______ ºC.
-20
The minimum battery voltage for APU start is ______ volts.
23.5
If the battery voltage drops below _____ volts, the battery must be physically removed from the aircraft by maintenance for recharging.
19
List the items on Hot Bus 1:
__________ _________
__________ _________
__________
ELT Engine Fire Bottle A
Fuel Shutoff Valve Eng. 1 Hyd. Shutoff valve eng. 1
Fuel pressure refueling
List the items on the Hot Bus 2 \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Courtesy/Stair lights Auto pos. Eng. Fire Bottle B
Fuel Shutoff valve Eng. 2 Hyd. Shutoff valve eng. 2
Main Door Control Fus fuel isolation valve
Fus fuel vent valve
The _________ override switch closes the relay provided the airplane in on the _________ with at least _____ generator(s) operative.
Shed bus
Ground
1
An illuminated strip in the button on the overhead panel means the switch in not in the normal _______ position.
flight
