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Flashcards in Electrical Deck (21):

What are the electrical sub systems?

(1) Electrical Power Management System (EPMS)
(2) Battery Subsystem
(3) Alternating Current (AC) Electrical Subsystem
(4) Direct Current (DC) Electrical Subsystem
(5) External Ground Power (EXT GND PWR) Subsystem


What are the EPMS Components?

(1) Master Ignition (MSTR IGN) switch
(2) Electrical Load Centers (ELC) 1 and 2
(3) Circuit Breaker Panels (CBP) 1 and 2
(4) High Power Switching Modules (HPSM) 1 and 2
(5) Utility Relay Panel


What are the battery sub system components?

(1) Battery
(2) Battery Charger


What are the AC Electrical Subsystem Components?

(1) Two AC Generators (GEN) 1 and 2
(2) Two Generator Control Units (GCU) 1 and 2


What are the DC Electrical Subsystem Components?

Two Transformer Rectifier Units (TRU) 1 and 2


What are the External Ground Power Subsystem Components?

(1) External Power Receptacle
(2) External Power Monitor (EPM)
(3) External Power Sense Switch


What do the HPSMs do?

(a) Power distribution
(b) Over current sensing
(c) Contactor switching logic for all AC, DC, and battery power requirements


What does the CBPs do?

Provide hard wired, unswitched circuit protection to meet system demands, receives power directly from the HPSM buses which are behind the specific CBP.


Where is CBP 1 and 2 located?

Behind the Pilot seat


What do the ELCs do?

Receive power directly from the terminals on the front of the HPSMs and routes the required power to the using component or system and provides circuit protection.


Where are the ELCs located?

ELC1 is located in the forward left EFAB
ELC2 is located in the forward Right EFAB


What Is the A/c primary source of electrical power?

Two 45 KiloVolt Ampere (KVA), 3 Phase, 4 wire, 115/200 Vac, 400 Hz, air cooled, brushless AC generators


How many volts is the DC Battery?

24 Volts


During a total electrical failure, how long with the battery last?

At 80% charge, will supply the normal flight battery loads for a minimum of 12 minutes


What do the GCUs do?

Manage the generator output, provides AC power to the HPSMs and disconnects the generator in the event of:
• Over voltage
• Under voltage
• Over current
• Under frequency
• Feeder fault between generator output and system load.


Both Generators Fail/Complete Loss of Electrical Power.

GEN1 and GEN2 – reset pilots GEN reset panel
If conditions persist,
Land as soon as possible


Single Generator and Single RTRU Failure

Affected GEN 1 or GEN 2 –rest pilots GEN reset Panel
If condition persists,
Land as soon as Practicable


What do the TRUs do?

Convert 115 Vac, 3 Phase, 400 Hz power from the HPSM AC bus to regulated 28 ± 0.5 V DC and provide DC power to the Battery Bus.


Dual TRU Failure

Land as soon as Possible


In the event of a dual TRU failure what can be expected by the pilot?

(a) TADS/PNVS and HDUs will be inoperative.
(b) All navigational functions will be lost.
(c) Some primary flight information will be lost (altitude, heading and airspeed).
(d) FMC functions will be lost.
(e) Stabilator control will be lost.
(f) Primary crewstation lighting will be lost.
(g) Engine Anti-Ice will activate.
(h) The Keyboard Unit will be inoperative.
(i) The crew will be able to transmit and receive on the preset radio frequencies but will not be able to input new frequencies with the keyboard unit.
(j) WPs will be inoperative and the Weapons System will not be functional.
(k) The ECS will be inoperative.
(l) The ice detector will be inoperative.
(m) The left and right pitot heater will be inoperative.


What is the note associated with GEN 2 failure?

Failure or reset of generator 2 can result in BUCS FAIL caution and FMC DISENGAGE cautions and a loss of one or more FMC channels. After completing the Generator Fail emergency procedure (GEN RESET), reset the BUCS FAIL and the FMC DISENGAGE by re-engaging the affected FMC channels. If the BUCS FAIL is not associated with the GENERATOR FAIL or the reset, the pilot should assume other problems have occurred and complete the BUCS FAIL emergency procedure.