Electrical System Flashcards
What are the DC power sources?
Main aircraft battery, GPU (external power), starter/generator
Where is the main battery located?
The aft fuselage compartment
What type is the main battery?
24 Volt DC, lead acid, 40 Amp-hr
What is the minimum voltage for a battery start?
22 volts
What does the battery provide power for?
Ground operations, engine start, emergency power
According to the DASH-1, external power (GPU) must provide how many volts and amps?
28-28.5 volts DC and 1000-1500 amps
Can the main battery supply power to all the buses and both inverters?
Yes
Where is the external power receptacle located?
lower left fuselage
What is a RCCB?
A specific CB not readily accessible to the pilot
What minimum N2 is needed for a functioning generator?
58%
What is the definition of an electrical bus?
connects electrical components in AC or DC lines
What is the output of the generators?
28 Volts DC, 400 Amp
What does the GCU (generator control unit) do?
provides regulation, control, and protection (allows generators to operate in parallel and share the load)
Where is the standby power switch located?
Copilots instrument panel
What are the max amps on the ground for each generator?
280 Amps
What is the max amps with both generators operating up to 41,000 feet?
280 Amps, each generator
What are the max amps with one generator operating up to 32,500 feet?
400 Amps
What are the max amps with one generator operating from 32,500 to 41,000 feet?
280 Amps
What minimum N2 is required for each generator to work?
58%
The standby bus is normally powered by the_______?
LH Load Bus
Where is the standby battery located?
24 Volt DC in the nose compartment
The standby battery is capable of powering which bus/buses?
Standby battery only
Under what conditions will the amber ON indication illuminate on the standby power switch light?
The standby battery is the only source powering the standby bus.
What aircraft equipment does the standby bus distribute power to?
Standby altimeter, standby attitude indicator, copilots instrument light power supply, UHF radio, engine EFC start, NO. 1 ITT indicator, RTU 1
What are the position of the master gen switches?
NORM and EMER
What are the AC power sources & where are they located?
2 inverters, 26 VAC & 115 VAC located in the nose compartment
What are the positions of the INV SEL switch?
NO 1, AUTO, NO 2
Where should the inverter voltage select switch normally be?
NO 1 INV, 115 VAC
What normally powers the NO 1 Inverter?
The LH load bus
Upon what conditions will the AC bus shed relay open?
When both:
-NO 2 inverter is powering the primary buses
AND
-NO2 inverter is being powered by the emergency bus
Normally, what powers the secondary AC buses?
The NO 2 inverter
Normally, how does the emergency bus receive power?
Through the emergency bus power feed line through the aircraft generators.
What happens if the battery switch is moved to the EMER position?
The main battery powers the emergency bus
What light illuminates if the third feeder line is active?
L or R BUS FDR FAIL, along with the Master Caution light
What provides a connection for all DC power?
The battery charge bus
What is the max operating load for single generator operation at FL200?
400 Amps
What kind of CBs protect the non-essential buses and radio masters?
switch CB’s
During the battery feed test with the battery switch in EMER, which of the following AC-assosicated annunciators should illuminate?
INV 1 FAIL and AC BUS SHED
What are the landing light limitations?
Do not extend: over 200 KIAS, or above 20,000 ft MSL
With the INV SEL switch in the NO 2 position, what does the #2 inverter power?
The primary AC buses & shed buses (primary buses only if powered by the emergency bus)
What does the ROTAT BCN switch control?
One red, rotating beacon light located on the tail
What lights are controlled by the NAV switch?
Navigation lights: one red on the left wing, one green on right wing, and one steady white light on the tail
What does the ANTI COLL panel switch control?
Three white, flashing anti-collision (strobe) lights, one in each wingtip and on the aft most point of the tail
What are the R and L wing inspection lights for and where are they located?
Inspecting wings for icing conditions, located on each side of the aircraft just forward of the wing root
How can you extend the landing lights with the gear up?
cycle the landing lights switches to RET/OFF and back to EXT/ON
When should the cabin general area floodlights automatically extinguish?
When the general area fluorescent lights illuminate, or when the aircraft is airborne
To arm the instrument floodlights for automatic operation, place the:_____
integral switch to the INTEG position
What will happen if the Integral Switch is in the INTEG position and the left load bus loses power?
Emergency lights will illuminate automatically
What happens when you test the emergency lights?
4 cabin lights come on (2 general are floodlights & 2 emergency exit lights), EMER LT NO ARM annunciator illuminates on the shroud panel
What powers the cabin emergency lights?
4 independent batteries
What kind of circuit breaker protects the LH and RH radio buses?
switch type circuit breakers
What are the three types of circuit breakers?
Remote Control Circuit Breaker (RCCB), Push-pull, Switch CB’s
What are the single generator failure indications?
MASTER CAUTION RESET and L or R GEN OFF annunciators, bad generator has zero volts/amps, good generator has slightly increased amps
How is the emergency light system controlled?
By a guarded switch on the overhead panel
What does illumination of the BATTERY FDR FAIL light indicate?
A ground fault, a feeder problem, or a battery feeder protection unit problem
What happens if you turn the battery off with a BATTERY FDR FAIL light?
Battery relay opens and the battery won’t charge
With a dual generator failure, how many amps should you see on the gauges?
0 Amps
What systems are lost with a single-generator failure?
None
What is powering the emergency bus if the EMER BUS FDR FAIL annunciator is illuminated and the CB is popped?
LH Load Bus through the EMER BUS-TIE relay
What does an illuminated BATT CUT OFF annunciator indicate?
Battery relay is open, no battery charging occurs, battery switch is in off or emer and electrical power is being supplied by one or both generators
When does the L or R BUS FDR FAIL light illuminate?
When feeder 3 (the “standby” feeder) is powered, indicating at least one of the other feed lines has failed
When does the EMER BUS FDR FAIL annunciator illuminate?
When the emergency bus power relay or the emergency feed RCCB opens and generator or battery power is not being fed through the emergency bus feeder line
What is the primary indication of an emergency bus feeder failure?
EMER BUS FDR FAIL annunciator
What is the 2nd indication of the emergency bus feeder failure?
Open CB
What hydraulic powered systems are affected when operating on EMER or STBY power only?
Normal gear extension, flaps, speed brake, anti-skid
What is the 1st step of the electrical fire checklist?
Oxygen masks-DON
THEN
ENSURE FUEL XFEED switch is in the normal position to prevent possible reduction in thrust
Can you reset FDR Bus CB’s?
NO
Where is the cabin smoke detector located?
Aft portion of the cabin
What comm/nav systems are powered by the standby bus?
RTU 1 and UHF radio
With a failure of the #1 inverter, what does the #2 inverter do?
Powers primary and shed buses
On the ground, what is the max allowable load on the operating generator?
280 Amps
What allows the generators to operate in parallel & share the electrical load?
The generator control unit (GCU)
How many bus feeders between the main & load buses are normally powered?
2
When operating on the EMER & STBY Buses, what trim systems are available?
EMER Pitch trim on the emergency bus
With the LDG lights extended and illuminated, if gear is then retracted, will the LDG lights retract automatically?
Yes
What controls the T-1A emergency lighting system?
The guarded EMER LT switch on the overhead panel
During flight, you observe a MASTER CAUTION RESET annunciator and INV 1 FAIL. What is the first thing you should do?
Check the respective circuit breaker
If the # 1 inverter fails, what will the #2 inverter power?
The primary AC buses
What does illumination of the Battery FDR FAIL light only indicate?
Battery feeder protection unit has failed or lost power
What does illumination of the Battery FDR FAIL light, EMER BUS FDR FAIL light, and MASTER CAUTION indicate?
Emergency bus feeder has lost power or the emergency bus feeder RCCB has popped
What does illumination of the Battery FDR FAIL light, EMER BUS FDR FAIL light, BATT CUT OFF and MASTER CAUTION light indicate?
The battery tie-in relay has opened and the emergency bus feed line has lost power. This might occur if the battery feeder protection unit has opened the relays because of a battery ground fault
If the EMER BUS FDR FAIl annunciator illuminates and it sCB is open what is powering the emergency bus?
the LH load bus (if it fails, the emergency bus will be lost)
When performing the ELECTRICAL FIRE checklist, which buses are powered when the Gen switch is in EMER and the Bat switch is off?
STBY bus only
Can you reset a BUS FEEDER CB?
NOOO
What does the BUS FDR FAIL annunciator indicate?
the standby feeder (#3) is powered
An illuminated AC BUS SHED annunciator on the pilot’s shroud panel indicates the:
AC shed buses are de-energized
During the battery feed test with the battery switch in EMER< which of the following AC associated annunciators should illuminate?
INV 1 FAIL and AC BUS SHED
