Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
35 Cards in this Set
- Front
- Back
|
How many networks make up the electrical system? Why?
|
2 independent networks
Redundancy and fault isolation |
|
|
What happens if a power generating source fails?
|
Bus ties automatically connect to provide no system degradation
|
|
|
What components power the AC system?
|
2 Integrated Drive Generators (IDG)
APU Inverter Ram Air Turbine (RAT) AC GPU |
|
|
What components power the DC system?
|
2 NiCad batteries
3 TRUs DC GPU |
|
|
How does the IDG maintain a stable power output?
|
A Constant Speed Drive (CSD) attaches the IDG to the Accessory Gear Box (AGB)
|
|
|
What monitors and controls the IDGs?
|
Each has a Generator Control Unit (GCU)
|
|
|
Can one IDG support the entire electrical system?
|
Yes
|
|
|
What will cause the amber IDG light on the overhead panel to illuminate?
|
High oil temp
Low oil pressure |
|
|
If an IDG is manually disconnected can it be reconnected by the flight crew?
|
No
|
|
|
What is the primary purpose of the AC generators?
|
Power the AC busses and AC ESS Bus which power the 3 TRUs
|
|
|
What is the purpose of the TRUs?
|
To convert 115 VAC to 28 VDC
|
|
|
Can the APU replace a failed IDG?
|
Yes
|
|
|
What is the AC electrical system's priority?
|
Onside (IDG)
Inside (APU) Outside (GPU) Cross-side (Other side IDG) |
|
|
How is it known that an AC GPU is hooked up and ready to provide power?
|
GPU button displays AVAIL and the GPU icon is presented on the electrical synoptic page
Once the GPU button is pushed in, it will display IN USE provided another AC power source is not available |
|
|
What does it mean if the AC GPU is plugged in and the outside GPU panel button displays IN USE?
|
Ground service bus is in use
Cockpit GPU button will display AVAIL even though ground service bus is in use |
|
|
If the airplane is using the AC GPU and the APU is started, what should the pilot be sure to do?
|
Deselect the GPU button before the next GPU connection
|
|
|
What will charge the batteries?
|
Any AC power source
|
|
|
How long will the batteries last without recharging?
|
10 minutes
|
|
|
What is the purpose of the DC GPU receptacle?
|
For APU start when batteries <22.5 VDC
If battery temp is <-20 |
|
|
What is the minimum battery temp for APU start?
|
-20 degrees C
|
|
|
What is the minimum battery voltage to close the battery bus ties?
|
18 volts
|
|
|
What battery is used for APU start?
|
BATT 2 powers APU Start Bus
BATT 1 powers the FADEC & EICAS monitoring |
|
|
What is the purpose of the inverter?
|
Converts 28 VDC from the batteries to 115 VAC to power the AC STANDBY BUS when an AC source is not available
|
|
|
What is on the AC STANDBY BUS?
|
Engine exciters 1A and 2A
|
|
|
What powers the Ram Air Turbine (RAT)?
|
Airflow turns the RAT propeller which spins the turbine inside
|
|
|
When will the RAT deploy?
|
Automatically if AC busses aren't powered
Manually by pilot |
|
|
How long after deployment will the RAT provide power?
|
8 seconds
|
|
|
Is there a total loss of power during the RAT deployment?
|
No. Batteries supply power to the DC ESS busses and AC STADNBY bus
|
|
|
What does the RAT power?
|
ESS busses
|
|
|
What is the minimum airspeed for the RAT?
|
130 knots
|
|
|
When is the RAT icon displayed on the electrical synoptic page?
|
When the RAT is deployed
|
|
|
What manages the electrical system?
|
4 Integrated Control Centers (ICC)
2 Secondary Power Distribution Assemblies (SPDA) |
|
|
What is an ICC?
|
Provides power distribution and protection for electrical loads
|
|
|
What is an SPDA?
|
An electrical load-management unit powered by the ICCs that distributes electrical loads to aircraft systems according to distribution logic
|
|
|
Can the flight crew reset the ICC and SPDA remote electronic CBs?
|
ICC - No, only by mx
SPDA - Yes, via the MCDU |
