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;
26 Cards in this Set
- Front
- Back
|
How is electrical power generated and stored on the DA42?
|
-It is generated via 2 60amp, 28volt DC alternators;
-It is stored via 1 10Amp-Hour, 24Vold DC lead-acid battery; 1 emergency power pack that consists of 10 lithium manganese 3V batteries; and 2 backup ECU batteries. |
|
|
Describe the alternators on the DA42.
|
-There are 2 total; 1 for each engine
-They output power at 28Volts DC and generate 60amps -They are belt driven mounted to the bottom of each engine -And they are controlled with alternator switches on the instrument panel. |
|
|
How many amps is the alternator circuit breaker?
|
70Amps
|
|
|
What is the purpose of the Alternator Control Unit?
|
-It measures the alternator output usage and controls current through the alternator field coils.
-It balances the load between the 2 alternators by putting more load on the cooler of the alternators. This is because the alternator output voltage is slightly decreased at higher temperatures. By putting more load on the cooler of the alternators, the system is more efficient. -They also include diagnostic functions which warn of under or over voltage. It displays a caution message on the G1000: "L/R ALTN FAIL" |
|
|
How does an alternator work?
|
-An alternator typically has a rotor which turns within a stator.
-The stator is a conducting wire wound about an iron core in which the current is generated. -The rotor is an electro magnet which has DC current applied to it in some form to create a magnetic field. -As the rotor turns, the magnetic field it creates cuts across the iron core windings and generates a current. The alternator field, in this case is just the magnetic field, which is either supplied by the alternator itself, once it is running, or by the excitation batteries. |
|
|
What is the purpose of the excitation batteries?
|
-They provide an electrical field for the alternator to generate electricity if the alternator's electrical field fails.
|
|
|
How many excitation batteries are their and what are their Volts and Amps?
|
-There are 2 excitation batteries. They are 12Volts and 1.3Amps.
-They are connected in series. There is NOT 1 per side. |
|
|
What is the significance of the engine master switch with regards to the excitation batteries?
|
It connects the excitation battery to the alternator field via a 5Amp fuse.
|
|
|
Where are the excitation batteries located?
|
The excitation battery pack is located in front baggage compartment forward of the forward cockpit bulkhead.
|
|
|
Where is the main battery located?
|
The main battery is located rear-right side of front baggage compartment.
|
|
|
Describe the main battery.
|
-It's a 24 Volt, 10 Amp-hr, lead acid battery.
-It's connected to the hot battery bus and the battery bus -The battery relay controlled with electric master switch on the instrument panel. |
|
|
What does the emergency power supply? For how long?
|
It runs the standby attitude indicator and the flood light for 1.5hrs.
|
|
|
How is the emergency power stored?
|
It is stored in 10, 3Volt 1300mAmp-hr, non-rechargable lithium manganese batteries. The batteries are taped together similar to a RC car battery pack.
|
|
|
Where is the emergency power battery pack located?
|
It is mounted behind the instrument panel on the pilot’s side (behind the PFD).
|
|
|
When must emergency power battery pack be replaced?
|
It must be replaced if seal is broken or if battery is used in flight.
|
|
|
Where is the external power jack and how many Volts does it supply?
|
It is located on the lower surface of the fuselage nose section.
|
|
|
How is the power distributed?
|
-It is distributed via a battery relay box located in the front baggage compartment next to the main battery.
-It connects the battery relay, starter relay, and the external power relay. -It also contains the LH and RH alternator relays. |
|
|
What is the hot battery bus?
|
-It powers the pilot map/reading light.
-It's connected to main battery relay via 20Amp fuse. -Power cannot be disconnected from this bus even with master switch off. |
|
|
What happens to the electrical system when the electric master is switched on?
|
The battery relay closes connecting the battery to the :
-Battery Bus -The LH/RH Main busses (via 90amp circuit breaker) -The LH/RH ECU busses |
|
|
What happens to the electrical system when the alternator switches are switched on?
|
The alternator relays close, connecting the output line of each alternator to the LH or RH “Main Bus” via a 70amp circuit breaker.
|
|
|
What happens to the electrical system when the engine masters are switched on?
|
It connects ECU A & B to the ECU bus and also connects the excitation batteries.
|
|
|
What happens to the electrical system when the engine starters are engaged?
|
It connects the starter relay to the battery bus.
|
|
|
What happens to the electrical system when the avionics master is switched on?
|
-It connects the avionics bus to the RH main bus via the avionics master relay.
|
|
|
What happens to the electrical system when the external power unit is plugged in?
|
-It essentially does the same thing as if the electric master was switched on. ie. Power is supplied to:
-Battery Relay -LH/RH Main Bus -LH/RH ECU Bus |
|
|
Will the avionics still work if the RH main bus fails?
|
No, the avionics bus is only connected to the RH main bus. So, if that fails, so will the avionics bus.
|
|
|
What systems are on the avionics bus?
|
-COM 2
-GPS/NAV 2 -Audio panel -Autopilot -Data Link (if installed) -WX 500 (if installed) |
