06 Electrics Flashcards
What is initiated by selecting the Battery switch to ON?
The L CCR start-up sequence
In the Generator Control (GEN CTRL) switch, what does the amber OFF light indicate?
The generator breaker is open
In the external power switches: -
a. What does the AVAIL light indicate?
b. What doest he ON light indicate?
a. External power is plugged in and power quality is acceptable
b. External power is selected ON
With an engine running, what is indicated when the generator DRIVE light illuminates?
A generator drive malfunction has occurred
In addition to traditional electrically powered systems, what other systems are electrically powered?
- Engine start
- Pressurization
- Wing ice protection
- Stabilizer trim
- Wheel brake systems
How many engine driven generators are there to power the main AC buses?
Four variable frequency engine starter/generators
What other aircraft power source for the main AC buses is available in flight?
Two variable frequency APU starter/generators
What AC power sources are available on the ground before engine start?
Three external AC power receptacles as well as the two APU generators
Can any of these AC power sources normally be connected to run together?
No
What electrical sources can be used for engine start?
- External A/C power
- APU generated power
- The opposite engine’s generated power
What electrical sources can be used for APU start?
Forward external power, APU battery, or engine generated power
On the ground, how many APU generators are available to power the main AC buses?
Both
If the APU is not available, how many external power sources are required for optimal engine start performance?
Three, both forward and one aft receptacle
How many primary batteries does the aircraft have?
Two, the Main and APU batteries
Can the Main battery be used to start the APU?
Yes, it assists the APU battery
What are the primary sources of power for the flight control electronics?
Three engine driven Permanent Magnet Generators (PMGs)
If PMG power is lost, what secondary sources of flight control power are available?
The 28Vdc bus distribution system, and the main battery
How are higher amperage loads distributed throughout the airplane’s electrical system?
They are distributed directly by the bus systems which are located in the forward & aft E/E bays (Primary)
How are lower amperage loads distributed throughout the airplane’s electrical system?
Via Remote Power Distribution Units (RPDUs) located throughout the airplane (Remote)
What is the purpose of the power conversion devices?
They change power from one voltage or current type (AC/DC) to another
How many main AC buses are there?
Four 235v AC buses, designated L1, L2, R1 & R2
What do the main AC buses provide power to directly?
A limited number of high voltage AC systems
How do the main AC buses provide power to other (lower voltage) bus systems?
Through power conversion devices
On the ground, with only forward external power selected ON, how are the main AC buses powered?
Via the 115v AC bus distribution system through the power conversion devices
