Electrical Flashcards
What HYD systems are Electric in 787
Stabilizer Trim
Spoilers
Main Wheel Brakes
What is the Location of the 3 electric power supply
FWD E/E Bay - 115 Vac and 28VDC
AFT E/E Bay - 235 Vac
What power supply is Ext
115 Vac usually both FWD
What power supplies are used for a normal start
Both FWD Vac and APU
or
Both FWD Vac and AFT Vac if APU is inop
(Supplementary procedure)
Only the Right eng can be started if Ext Pwr is the only source
What Converters are on board
235 Vac –> 28 VDC
115 Vac –> 235 Vac to operate Hyd pumps Eng starters NGS
What AC buses do we have
L1 Main
L2 Main
R1 Main
R2 Main
When APU or Eng gen online they supply 235 Vac which converts to 115 Vac and 28 VDC pwr
What generators does the APU have
2 - 235 Vac starter/generators
How can APU start be powered
APU bat
Ext Pwr
Eng Gen
(one started is used for APU start but both generators available after for pwr delivery)
Describe the Eng Starter/Generators
2 - 235 Vac on each eng L1, L2
unlike the APU both starters assist in eng starting
Where does the 235 Vac power from the eng go
to the AFT E/E bay
In normal operation which gen supplies which bus
L1 - L1
L2 - L2
R1 - R1
R2 - R2
After the Buses where does the 235 Vac power go
Large Motor Power system
In AFT E/E Bay, and cooled by the PECS
What are RPDU’s
Remote Power Distribution
used for lower amp loads through 17 units throughout the aircraft
Where can you see the systems Load Shed?
Synoptic
SYS - ELEC page, bottom middle
Where does the power for starting eng 2 come from
assisted by Large Motor Power System
indicated on the Synoptic page
What batteries are on board?
2 - 28 VDC
Main Bat - FWD E/E bay
APU Bat - AFT E/E bay
What powers the Flight controls
3 Permanent Magnet Generators
L1, L2, R2
(ensures power to the flight controls is independent to the rest of the system as long as one eng is rotating)
What powers the brakes
4 power supplies in the FWD E/E
2 separate 28 VDC inputs from the primary power source and from the MAIN Battery
What is the BPCU
Bus Power Control Unit
Electronic controller that determines the power distribution for different configurations
Flight deck control and indication
Determines different Modes
How does the BPCU protect systems
Load Sheading
Load Inhibiting
What type of circuit breakers
ECB’s - Electronic (indication and control)
TCB’s - Thermal (just Indication)
What are the Two type of power distribution methods?
Primary and Remote
What does turning the Battery on do when first arrive at aircraft
ON-Ground Battery Only Mode
allows the power up sequence
APU start capability
CCR L (CDU screen on)
What starter is used when APU started with Battery power
Right Starter on APU
Where does the APU power go
235 Vac Busses
What is powered with only one FWD Ext Pwr source
FLT Deck Equipment
Cabin Systems
Cabin Lighting
PECS (single loop)
What is powered with 2 FWD Ext Sources
NGS HYD IFE Cabin Systems Cabin Lighting PECS (Both Loops)
Does the Main Battery have to be on for Ground Handling Mode
NO
just one Ext Source
(mostly service and cargo items)
Does the Main Battery have to be on to turn on Ground service mode by the flight Attendants?
No
an extension of the Ground Handling mode and allows the FA’s to turn on systems without pilots there
What is the Priority sequence of the Power sources
Eng
APU
Ext Pwr
What powers what buses with one eng started by APU
running eng powers the 2 buses on the same side (R1 R2)
APU powers the 2 other 2 buses (L1 L2)
When does the APU automatically start
3 or more eng generators go off line
When does the RAT automatically deploy
Loss of electrical power to the CA and FO flight instruments (In air Rat mode)C
(MAIN Bat supplies until RAT deploys)
What is the difference between the RAT and Main Bat supply
Center Pitot heat not energized
What is the CBIC system
Circuit Breaker Indication and Contol
on SYS - MFD - CB
When do you get a confirmation window when opening and closing a CB
In Flight
