Electrical Power System Flashcards
How much power is provided by the electrical power system? Via what components?
115 V AC and 28 V DC
2 L/R GEN (AC) and L/R 2 TRU (DC)
What is a TRU? What does it do?
transformer-rectifier unit, converts the 115 V AC into 28 V DC
How many batteries, with what capacity?
2x 28 V DC
Do any of the generators produce DC power?
Yes, the APU DC GENERATOR (28V DC 180A)
What frequency range do the 2 AC Generators operate in?
250-520 Hz
How many AC busses are there and what are they?
2, XP1 left and XP2 right
How many DC busses are there and what are they?
5;
main, essential, ground (com1/2 available on ground), battery, hot battery (permanently energized, independent from BATT switch)
What items are on the hot batt bus?
canopy, seat pan, fuel SOVs, fire extg’s, IN/GPS
How long can the two batteries provide emergency power (with and without load shedding)?
18 mins, up to 30 w load shedding
T/F: Both generators are required to carry the entire electrical load of the aircraft.
False, a single generator is capable of carrying the entire load alone.
What voltage is expected when DC power is being supplied by APU?
25.0-28.0V DC
What voltage is expected when DC power is being supplied by the TRUs?
27.5-31.5V DC
What must you do if the BATT voltage is below 23.2V on start?
wait 22 mins before takeoff to allow adequate battery charging
Batt switches must be set to ON at the same time (within ___ sec from each other) in order to perform a correct _____.
7, PBIT
Within 4 sec from Batt switches to ON position, expecting what light to mean good PBIT?
BATT light
T/F: Moving batt switch to off with at least one engine running disconnects batteries from associated batt busses as well as the essential bus.
False, can only disconnect from essential bus w one+ engine(s) running.
Above what temperature is the battery automatically disconnected L/R BATT from the essential bus? Reconnected?
+65C +/- 2C
+55C
If batt is not auto disconnected and the temp > +71C, what do you expect?
L/R BATT T
APU starting the A/C may not be guaranteed due to battery performance degradation at temperatures below _____.
-15C
Which external power source, AC or DC, will energize all A/C AC and DC busses?
AC
What do you expect to lose with a LEFT ESSENTIAL BUS FAIL?
VOR/ILS
TACAN
IFF
FWD UFCP
FWD CSD
FWD center MFD
ECS system (OBOGS, pressurization)
COMM2
L ENG IGN
NWS
UCB
What do you expect to lose with a RIGHT ESSENTIAL BUS FAIL?
DC FUEL PUMP
IN/GPS
COMM1
rear HUD/UFCP
LEFT MFD
MCSG
R ENG IGN
