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?
(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?
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.