Electrics Flashcards
How many generators (including APU) can power all electrical needs?
1
In flight, during generator failure, what is automatically shed?
Main galley power
What is the main difference between when Gen 1 fails versus Gen 2?
Gen 1 is connected to the Essential Bus and Shed while Gen 2 requires the AC ESS FEED button depressed
When RAT deploys, what does it power?
AC and DC ESS BUS and SHED
In an emergency what does BATT 1 power?
AC ESS BUS through inverter
In an emergency what does BATT 2 power?
DC ESS BUS
What are the electrical priorities?
G enerators E xternal Power A pu generator R am air turbine B atteries
What are the capacities of the generators and the APU?
90 KVA
3 phase
115-200 V
400 Hz
What are the capacities of the emergency generator?
5 KVA
3 phase
115-200 V
400 Hz
What do the (TR) transformer-rectifiers do?
Convert AC to DC
When will you see a green arrow connected to the battery?
only when current is >1 amp
What are the limitations for the IDG FAULT buttons?
Do not depress more than 3 seconds.
Engine must be running or windmilling
Can be reset on ground only
When will you get the IDG FAULT light on?
High IDG oil temp
Low IDG oil pressure
When will the batteries start charging?
<26.5V
When will the battery contactors close?
AC BUS 1&2 not powered by other sources (no EMER GEN during flight, worst case)
When will the auto batt cut-off?
Ground BAT in AUTO AC power source N/A Batt voltage low (reset by cycling BAT buttons)
How long are batteries prevented from charging after APU start?
30 minutes
During preflight, what white lights should be present on the ELEC panel?
None!
When you turn on the battery what is the max charging current allowed?
<60A and decreasing within 10 seconds
What tells you that the APU is powering the AC?
AVAIL light on the APU START button AND AVAIL light on the EXT POWER button
When you start engine 2, what happens to the bus tie?
Opens, APU now powers BUS 1 and Generator powers BUS 2
RAT & EMER GEN FAULT light is on, what does this mean?
The RAT takes 8 seconds to spool up before coming on-line, during this time you are running off the batteries.
What is the min speed for the RAT to function?
140kts
During landing, at what speed does the EMER GEN become unavailable?
125kts
What happens below 50kts during total electrical failure?
All displays blank
Braking and engine control
VHF1
NO nosewheel steering
Right side dome light main panel flood lights (left two columns only) and the standby compass light.
Which cockpit lighting is available during an emergency electrical situation?
A static inverter transforms DC power from Battery 1 into one KVA of single-phase 115v/400hz AC power which is then supplied to part of the AC essential bus.
What is the function of the static inverter?
The aircraft has two types of C/Bs. Monitored (green): When off for more than one minute the C/B TRIPPED warning is triggered on the ECAM. Non-monitored (black).
How many types of circuit breakers has the aircraft?
No.
Can you reconnect an IDG in flight?
Two engine generators one APU generator and one external power source.
AC Power (115v) can be provided by which power sources?
Engines external power APU.
What is the order of priority for the different generators?
I have to check that the BAT pushbuttons are on and switch the external power on.
If the battery voltages are below the minimum how do you charge them?
Electrical power to both AC BUS #1 & #2 is lost and the aircraft speed is above 100 knots.
When does the RAT automatically deploy?
No.
Is it possible to connect the engine driven generators in parallel?
External power is supplying the aircraft electrical systems.
What does the blue EXT PWR ON light mean?
It is a reminder that the main galley has been shed automatically following the loss of one generator.
After IDG disconnection why do you get a GALLEY SHED indication in the SD?
No but some loads are shed in both main galleys.
If both engine generators are powering the system and one subsequently fails are any busses unpowered?
The GAPCU controls the frequency and voltage of the APU generator / external power output protects the network by controlling the emergency generator line contactor and controls the emergency generator start-up.
What is the purpose of the Ground and Auxiliary Control Power Unit (GAPCU)?
The ground power connector is near to the nosewheel on the right side of the fuselage.
Where is the ground power connector?
The contactor of each TR opens automatically in case of overheat or minimum current. The other TR automatically replaces the faulty one. The ESS TR supplies the DC ESS BUS.
What occurs in case of a TR fault?
By pushing the EXT PWR Pb thus disconnecting the external power.
Having started the APU with external power connected how can you get the APU generator to power the electrical system?
The blue hydraulic via the RAT.
What powers the emergency generator?