Falcon 20 F Retrofit Electrical Flashcards
What are the four sources of electrical power for the aircraft?
Generators, Batteries, APU, GPU
What is the APU rating?
27.5 to 28.5 Volts/300amps
What is the battery rating?
24 - 26 volt/ 36 Amp hour
What is minimum battery voltage to start the engines?
22 volts
Why is 22 volts the minimum required to start the engines?
It takes 18 volts to close 4 P (reverse current relay) and 8 - 10 volts to keep it closed
If battery voltage is below 18 V before the preflight what action must be taken?
Unless the aircraft has SB 172, the batteries must be removed from the aircraft and recharged
How many current limiters protect the batteries?
The #1 battery has 2, and the #2 battery has one current limiter
When checking the current limiters, what would a zero indication on the amp gauge mean?
If the amp gauge is at zero when the #1 battery is turned off, this would mean that the #2 current limiter was bad.
If the battery light illuminates on the master caution panel what does it mean?
Either one or both of the batteries are disconnected from the electrical system.
What would cause one or both of the batteries to disconnect from the electrical system?
- Battery switches are off
- Battery relays failed
- 4P (reverse current relay) is open
How would the pilot know what the cause of battery disconnect is (besides the obvious battery switch being turned off)?
- If 4P (reverse current relay) - no voltage showing on the gauge
- If one or both battery relays failed then voltage will be shown on the gauge
How many amps will cause 4P to open?
400 amps
When do the battery WARM and battery HOT lights illuminate?
WARM - 120º C
HOT - 150º C
What is the maximum number of battery reset attempts allowed?
2
How many batteries are on board the Falcon 20?
Seven
- 2 main batteries
- 1 emergency lighting
- 1 jet pack
- 3 standby computer batteries
How long will an emergency battery pack last?
40 minutes
How are the emergency batteries charged?
Through a rectifier from the No. 2 AC inverter.
In the armed position, when do the emergency lights illuminate?
Total loss of power to the main bus.
What does the EMERG BATT annunciator indicate?
The emergency battery is in use.
What are the GPU power settings for the Falcon 20?
28.5 volts/ 1000 amps
When performing a GPU start, when do the BATTERY and GEN lights extinguish?
- The battery will extinguish when the DC power selector is moved to normal.
- The GEN lights will extinguish when the GPU is unplugged from the airplane.
What items are on the battery bus?
- Fire Extinguishers
- Battery Control
- Service Lights
- Pressure Refuel (With SB 400)
How many electrical buses are in the system?
How many load shed buses are in the system?
11
5
How are the load shed buses isolated?
Aux bus switch
What are the functions of the aux bus?
- Allows C,D, E and F load shed buses to be powered by the main bus. Sheds 70% of the electrical load
- Disables standby inverter operation on the copilot’s side during load shed.
- Allows service lights to function even if battery switches are off.
- Powers maintenance panel in rear baggage compartment for checking oil and filter bypass (retrofit model only)
What is the color of the load shed breakers (C.B.s?)
Red
What are the generators regulated to?
28.5 Volts and 300 amps
What are the maximum generator volts?
32 Volts
When do the starters become generators?
50% N2
If the generator light is still on after start, and the generator is producing amperage then the start relay has welded shut. Describe the scenario for shutting down.
- Turn number 2 battery off.
- DC Power selector to cold start.
- Shut down the engines.
- Disconnect #1 and then #2 batteries
What are the 3 main functions of the generator switch?
- Circuit protection
- ON/OFF
- Starter interlock
What should be the maximum split on the generator output?
10% amperage
What is the purpose of the GCU?
- Terminates starts at 50% N2
- Regulates 27 volts
- Parallels the load
- Limits output to less than 300 amps
- Provides progressive field weakening during engine starts
- Trips generator at 31 volts
If a generator light comes on and the corresponding generator switch has tripped, what would be the cause?
A direct short or over voltage.
What are the maximum number of generator resets?
2
If generator 1 and 2 lights come on simultaneously what can the pilot do?
Dual generator failure - see checklist
With a total electrical failure, how do you extend the gear and the flaps?
Hand crank the flaps or land clean wing. Extend the #2 hydraulic system.
