PC-21 Electrical System Flashcards
What is the purpose of the PC-21 Electrical system?
To supply and control 28 VDC to various aircraft systems
How does the electrical system ensure that power is always available to the aircraft equipment under differing operational requirements?
Through a series of busbars as well as manually and automatically controlled contactors.
What are the three sections that is a good way to think about the electrical system?
- Engine compartment
- Cockpit
- Avionics Bay
What electrical components are located in the engine compartment?
1) BATT 1, located on the lower left side of the engine compartment
2) GEN 1 and 2, which are engine driven through the AGB
3) Generator Control Units 1 and 2, which are mounted on the firewall at the rear of the engine.
4) Circuit Breaker (CB) panel on the right-hand side of the engine compartment
What are specs of BATT 1? What are its functions?
- 24 VDC, 25 Ah sealed lead-acid battery
- Supplies power to the BATT BUS and is essential for engine start, supplying power to GEN 1.
What are the specs of the generators?
- 28VDC
- Rated at 300 A
What is GEN 1 employed as?
- Combined starter/generator
- Generates DC Current
What is GEN 2 employed as?
Generator only
What is the function of the GCU?
- Maintain correct voltage from generator
- Protect the electrical system against over/under voltage
- Protect the system against overload
- Protect the system against reverse polarity
- Protect the system against reverse current
Where is the engine compartment CB panel?
Located at the top right hand side of the engine compartment
What is used to control the electrical system in each cockpit?
- ELEC panel on right console in each cockpit.
- 5 switches and push button in front cockpit
What are the switches in the front cockpit ELEC panel?
- BATT 1
- BATT 2
- GEN 1
- GEN 2
- BTC NORM (but tie override switch)
- RESET
Where is the cockpit CB panel located and what is it essential for?
- Right side wall of the front cockpit above the console.
- Contains circuit breakers that are essential for IFR flight.
What are the components in the avionics bay?
- BATT 2
- Emergency Battery
- Avionics Bay CB panel
- Ground Power Unit (GPU) connector, bottom left surface of the fuselage
What are the specs of BATT 2? What does it provide power to?
- 24 VDC, 18 Ah
- Power to BATT BUS and BATT DIRECT BUS
What are specs of Emergency Battery?
- 24 VDC, 2.5 Ah, sealed lead-acid battery
- Supplies to EMERGENCY BUS when all electrical power supplies are lost in flight.
How many distribution bus bars are there?
7
What is basic architecture of PC-21 electrical system?
- Four primary power sources (Generators and Batteries)
- Emergency battery
- Electrical bus bars
What are the 7 buses that are installed in the PC-21?
- BATTERY BUS
- BATT DIRECT BUS
- GEN 1 BUS
- GEN 2 BUS
- EMERGENCY BUS
- NON-ESSENTIAL BUS
- MISSION BUS
Which buses does GEN 1 supply during normal operating conditions?
- GEN 1 BUS
- BATT BUS
Which buses does GEN 2 supply during normal operating conditions?
- GEN 2 BUS
Where does MISSION BUS and EMERGENCY BUS receive power from?
BATT BUS