Electrical Flashcards
What are the sources of airplane generated AC power?
- 2 Engine Driven Variable Frequency Generators: 115 VAC, 360-650 Hz, 60 kVA
(67.5 kVA for 5 minutes; 75 kVA for 2 minutes; 90 kVA for 5 seconds); - 1 APU Generator: 115 VAC, 400 Hz, 60 kVA to 45,000 ft // 40 kVA above 45,000 ft.
(67.5 kVA for 5 minutes; 75 kVA for 2 minutes; 90 kVA for 5 secs); - 1 RAT (Ram Air Turbine): 115 VAC, 400 Hz, 9kVA, when all other AC sources have been lost.
(13.5 kVA for 5 minutes, 18 kVA for 5 secs)
How many AC Buses does the Electrical System have?
3 Total. AC Bus 1 / AC Bus 2 / AC Essential.
How long will the Aircraft Batteries last as the sole source of power?
- They will last a Minimum of 5 minutes as the sole source of power.
Note: Different than the 4 Emergency Batteries (ELPS – Emergency Lighting Power Supply batteries trickle
charged from DC ESS Bus 1) that can provide a minimum of 15 minutes if fully charged.
What is the purpose of the PPDS (Primary Power Distribution System)?
- Protects, Controls and Distributes AC/DC power to the AC/DC Buses.
In the event of Single Generator Operation, which AC Buses are Automatically Shed?
- None. A single Generator supplies power to all 3 AC Buses (although some high load users, such as
certain Hydraulic System pumps are load shed). - Note: One Generator can supply power to a maximum of 2 Hydraulic ACMP.
- APU Generator provides power above FL430 to only 1 Hydraulic ACMP.
What does an EXT AC “AVAIL” annunciator on the Electrical panel indicate?
- External AC power is connected with correct Voltage & Frequency but not yet on line.
Where is the location of the External Ground Power Panel?
- Lower body fairing below the right engine.
Which buses are powered with EXT AC connected, On and in Normal Mode?
All AC & DC Buses are powered.
What is the AC Priority Source for AC Bus 1 & 2?
- Onside Engine VFG (Variable Frequency Generator);
- APU Generator;
- External AC Power;
- Opposite Side Engine VFG (Variable Frequency Generator).
What is the AMP rating of the TRUs?
- 300 Amp up to 40,000 ft;
- 250 Amp above 40,000 ft.
What are the 6 DC Buses?
- MAIN BATT Bus;
- APU BATT Bus;
- DC Bus 1 & 2;
- DC ESS Bus 1 & 2.
What are the 5 Primary DC power sources?
- MAIN BATT;
- APU BATT:
- TRU 1, TRU 2, ESS TRU.
What is the Voltage and Ampere-Hour rating of the batteries?
24 VDC and 28 Ah.
Where are the APU and MAIN Batteries located?
- APU Battery is in the Belly Fairing compartment below the Baggage Bay Door.
- Main Battery is in Forward Equipment Bay in the Nose of the Airplane.
How do you know when a Battery is Not being charged?
- A Cyan DISCHARGING indication on top of the battery on the ELEC Synoptic page;
- A Cyan “BATT DISCHARGING” CAS message.
Which DC Buses are automatically Shed during Single TRU Fail?
NONE. All remain powered.
Which DC Buses are automatically Shed during a TRU 1 & TRU 2 Fail?
DC Bus 1 & 2.
Can the pilot reset a thermal circuit breaker from the ECB (Electronic Circuit Breaker Application)?
- No. The affected Thermal circuit breaker can only be manually reset at its location.
Will a physical CB trip generate a CAS message?
- Yes. A Cyan “CB TRIP” CAS message will be displayed.
How do you determine the location of an open CB?
By viewing the location on the CB application.
When does the RAT automatically deploy?
- In the event of a complete loss of AC power in flight.
How can the RAT be stowed?
On the ground only by maintenance.
If the RAT Generator trips offline, how can it be reset?
By moving the RAT deployment handle to Stow and back to Deploy position.
When does the RAT generator go Offline?
-Below 147 kt. (Get configured and set your Stab Trim to Vref before slowing down below 147Kts).
-Note: Try landing with min of 115 kt to avoid going into Direct Mode (110 kt).
If a Generator resets after a RAT has deployed, which Buses will the RAT power?
AC ESS Bus.
