Review Questions - Electrical Flashcards
What starts the battery charging cycle on the ground?
Selecting the BATT pushbuttons to AUTO with EXT PWR ON.
Charging cycle takes approximately 20 minutes
Will the batteries completely drain if you leave the BAT switches in AUTO after AC power is removed?
No. Battery cut-off logic prevents complete discharge when the aircraft is on the ground and unpowered – 22VDC
How is the BATTERY BUS normally powered?
DC BUS 1 through a DC tie contactor
DC BUS 1 is supplied from TR1
What does the amber FAULT light in the GALY & CAB pb indicate?
At least 1 generator load is above 100% rated output
How does the GALY & CAB pb work in AUTO?
a. Sheds main galley and in-seat power supply if:
b. Only 1 generator (APU or Engine) is available in FLIGHT, or
c. Only 1 ENGINE generator is available on the GROUND
What does a FAULT on the ENG GEN pushbutton indicate?
The generator line contactor is open because of a fault detected by the Generator Control Unit (GCU) which could include:
a. Overload
b. Over/under voltage
c. Differential fault (short), and/or;
d. The generator line contactor is open
What does the APU GEN FAULT light indicate?
The generator line contactor is open because of a fault detected by the GCU
What is the function of the BUS TIE in the AUTO position?
a. Allows the BUS TIE CONTACTORS to open and close automatically to maintain power to both AC BUS 1 & 2:
b. Allows a single source to power the entire system
c. Allows connection of the APU GEN or EXT PWR to the system
d. Inhibits multiple sources to connect simultaneously
What does an IDG FAULT light indicate?
OOL
a. Oil pressure low (inhibited when N2 < 14%)
b. Oil outlet temperature overheat
c. Light is inhibited when IDG is disconnected
What precautions must be taken when disconnecting an IDG?
a. Disconnect only when the engine is running or windmilling
b. Do not hold button longer than 3 seconds
How can an IDG be reset?
On the ground by maintenance
What is the function of the AC ESS FEED pushbutton in the normal position?
Allows AC BUS 1 to power the AC ESS BUS
How is AC ESS FEED transferred from AC BUS 1 to AC BUS 2?
Manually by selecting ALTN on the AC ESS FEED pushbutton or automatically if AC BUS 1 is lost and the switch is in the normal position.
What does the AC ESS FEED pushbutton white ALTN light indicate?
AC BUS 2 is powering the AC ESS BUS
What is the purpose of the static inverter?
To provide AC power to the AC ESS bus from the battery when the EMER GEN is not online when in the Emergency Electrical Configuration
What are the 3 times the batteries are connected to the BATTERY BUS?
a. APU start
b. Battery charging
c. AC BUS 1 & 2 not powered and airspeed below 100 knots
What is the priority sequence for electrical power?
GEARB
Generators - Engine
EXT PWR (manually selected)
APU Generator
RAT Emergency Generator
Batteries
What is the significance of the green and red collared circuit breakers on the Flight Deck?
Green – Monitored by ECAM system
Red – Wing tip brake C/B
Black – Not monitored by ECAM
What buses are powered by the emergency generator?
AC ESS and AC ESS SHED
DC ESS and DC ESS SHED
What is the function of the MAN ON pb on the EMER ELEC PWR Panel?
AUTO - RAT will automatically extend if AC BUS 1 & 2 are not powered and airspeed > 100 knots
MAN - extend the RAT at any time
How long does it take the RAT to extend and provide power?
8 seconds (3 seconds for RAT extension, 5 seconds to pressurize the Blue hydraulic system and power the EMER GEN)
What does the red RAT & EMER GEN fault light on the EMER ELEC PWR Panel indicate?
The emergency generator is not supplying power when AC BUS 1 and AC BUS 2 are not powered
What powers the emergency generator?
Blue hydraulic power from the RAT
What is the difference in functionality of the MAN ON pb (EMER ELEC PWR Panel) and the RAT MAN ON pb (HYD Panel)?
Deploying the RAT with the RAT MAN ON pb on the HYD panel only provides Blue Hydraulic pressure - No emergency generator.
What happens when you push the GEN 1 LINE pushbutton?
a. GEN 1 Line Contactor opens and the white OFF light illuminates
b. AC BUS 1 is powered by GEN 2 through the BUS TIE CONTACTOR
c. GEN 1 continues to power 1 fuel pump in each wing tank
When is the GEN1 Line pushbutton used?
During smoke procedures
What does the amber SMOKE light in the GEN 1 LINE pushbutton indicate?
Smoke is detected in the avionics bay
How would you know if the Blower and Extract fault lights were due to smoke?
SMOKE Light on the EMER ELEC PWR Panel and an ECAM warning
