Elec Flashcards
AC voltage / frequency?
Engine Gen / APU apparent power?
Emer Gen apparent power?
DC voltage?
115/200V, 400Hz, constant frequency
90 kvA
5 kvA
DC 28 V
What do the GCUs / GAPCUS do?
What does a GCU (Emer Gen) do?
Generator Control Unit
Ground / APU Control Unit
- Control frequency / voltage
- Protect network via line contactor
Emer Gen GCU
* Controls speed / voltage
* Protects network via line contactor
* Controls start up
Which battery is the Static Inverter connected to?
How much apparent power supplied, to where?
What if BAT sw off?
When does it cut out?
Battery 1
1kvA to AC ESS BUS
Works regardless of battery switch position
Cuts out at 50kt (if BAT pb OFF)
Otherwise not
What is the current of the TRs?
What controls the TR line contactors?
200A DC
Each TR controls its own contactor
What is the battery capacity?
How are the battery contactors controlled?
23 Ah each
Each battery has its own Battery Charge Limiter (BGL) which controls the contactor
What are the three groups of monitored CBs? (Green caps)
Which CBs have red caps? Why?
- OVHD PNL
- ELEC BAY (L/R)
- REAR PNL
- JM / NR / SV / WZ
WTB have red caps to prevent reset
What is the difference between CLR and EMER CANC?
CLR: Clears all notifications from the same panel until CB reset
EMER CAN: clears all notifications for the rest of the flight
Can generators be connected in parallel?
No
In normal config, which busses does TR 1 power?
- DC BUS 1
- DC BAT BUS
- DC ESS BUS
Are the batteries continuously connected to the DC BAT BUS?
No- Battery Charge Limiters only close the contactors when:
- Battery voltage below 26.5 V
opens again when charge current below 4A- or 30 mins after that in flight - Loss of AC1+2 and under 100kt
- APU starting (until 95%)
Maintenance Bus ON: and aircraft network OFF
Which busses are the EXT PWR feeding?
AC GND/FLT BUS
DC GND/FLT BUS via TR2
Bypasses aircraft network.
Abnormal
What happens with the loss of one generator in flight?
Other GEN powers both sides. APU can take up the load of the failed Gen.
part of Galley automatically shed
Abnormal
What happens if a TR fails?
Why might a TR fail?
Other TR replaces the faulty one
(opposite DC fed via the bat bus)
ESS TR supplies DC ESS
It opens its own contactor due to
* overheat
* below minimum current
Abnormal
What happens if both TRs fail?
DC1, DC2, DC BAT busses lost
DC ESS fed by ESS TR (from AC ESS)
Abnormal
What happens if AC BUS 1 fails?
Which button might we need to press?
How long to wait until DC BUS 1 and DC BAT BUS come back online?
AC BUS 2 can supply AC ESS BUS (+ ESS TR + DC ESS)
via AC ESS FEED pb
(unless autoswitching installed)
DC BUS 2 supplies DC BAT and DC BUS 1 after 5 sec.
Abnormal
Dual Generator Fail
What are the conditions for the RAT dropping automatically?
What does the RAT power and how?
What happens when the RAT stalls?
If on batteries only, when can the APU be started?
ADIRS1 IAS over 100kt
AC BUS 1 + AC BUS 2 lost
RAT powers BLUE HYD, EMER GEN generates 5kvA power for AC ESS
also powers DC ESS via ESS TR
RAT stall- AC + DC SHED are shed
Below 50kt, AC ESS also shed (screens)
APU can only be started below 100kt on batteries
EMER ELEC
What is the difference between the
RAT&EMERGEN (EMER ELEC) pb
and the
RAT MAN ON (HYD) pb?
EMER GEN uses solenoid 1
HYD uses solenoid 2
GCU only connects to AC ESS / ESS TR
if EMER GEN pressed
OR AC1/2 OFF (>100kt)
Abnormal
What is the difference between EMER ELEC and Smoke Config?
Roughly how much equipment is shed? What does remain?
GEN 1 still powers the fuel pumps via the GEN 1 (fuel pumps upstream of the contactor)
Sheds around 75% of equipment
Overhead panel is what remains
Abnormal
What is the delay for APU start being available after dual generator fail?
45 sec
this is to prevent interference with EMER GEN coupling
What does the BAT 1(2) control?
Can they remain closed all the time on the ground?
What is still supplied when they are OFF?
What does a FAULT light mean?
The battery charge limiters
No, there is a limit to stop complete discharge on the ground when in AUTO
BAT BUS and HOT BUS
BCL fault- ECAM alert if charging current out of limits.
Why would the IDG fault light come on?
When will the IDG disconnect thermally?
- Oil outlet overheat (over 180º)
- IDG low pressure
ignored when N2 uner 14%
200º C automatic thermal disconnect
What happens when the generator switch is in auto?
Why would a generator pb show an amber fault light?
Why might you only get two reset attempts?
The generator field is energised, line contactor closed (if electrical parameters normal)
de-energised and contactor opened when OFF
- associated GCU tripped
- opening of the line contactor
In case of a differential fault causing the GPU to trip
What does the BUS TIE pb OFF mean?
When would one contactor be closed?
When would both contactors be closed?
Both bus ties are open
One closed when
* one engine generator supplies its own AC BUS
AND
* APU or external power supplies the other side
Both closed during single engine ops or APU / Ext Power powering everything
Why would AC ESS FEED pb show ALTN?
AC ESS supplied by AC 2
- needs to be pressed unless automatic switching installed
When is the galley shed when the GALLEY pb in AUTO?
What does the GALLEY supply in the flight deck?
What does the amber FAULT light mean?
When in OEI
Comes available again when APU/EXT PWR online (ground only)
Supplies EFB charging
Amber GALLEY FAULT- either generator over 100% of rated output
After how long does the Emergency Generator connect to the network after the RAT starts to supply it?
What does a red FAULT mean?
3 sec
(8 sec total including RAT deployment)
Red FAULT on pb means AC 1 + 2 dead and EMER GEN not supplying either
What does the EMER GEN TEST pb do if pressed and held?
If AC 1+2 are powered:
* EMER GEN powered by BLUE HYD
* AC+DC ESS connected
If on batteries only:
* Static inverter powers AC ESS
What happens when GEN 1 LINE pb turned OFF?
(e.g. SMOKE EMER CONFIG)
What does the SMOKE lt mean on the GEN 1 LINE pb?
- Gen 1’s line contactor opens
- AC 1 fed by GEN 2
Smoke detected in the avionics ventilation duct.
What do NOT IN USE and EXT PWR AVAIL mean on the under nose panel?
NOT IN USE white light- cleared to disconnect
EXT PWR AVAIL amber light- available and voltage correct
When the maintenance bus is OFF, what are the AC+DC GND/FLT busses connected to?
What services are connected to the AC + DC GND/FLT busses?
When OFF, AC+DC GND/FLT busses connected to AC2/DC2 (so will be killed when aircraft network powered down)
- Cabin/galley/entrance/lav/cargo/dome lighting
- Lav service
- Vacuum sockets, cabin/flt deck
- Yellow Elec
- FQI, refuelling
- Gear bay lighting
- Belly service panels
- Ground call
- Equipment compartment lighting/service
- Nav lights
- PA / Interphone
ECAM
When will the battery voltage show in amber?
When will the battery current show in amber?
When is the battery contact arrow green / amber / green line only?
When below 25 V / above 31 V
When above 5 Ampères
Green- charging, over 1A
Amber- discharging, over 1A
Green line- closed, current under 1A
Why would the DC BAT label be amber?
The DC battery voltage is 25 V or less.
What does it mean if the AC1 bus label is amber?
How do we know if the AC / DC ESS SHED has been dropped?
The bus is not power.
Amber SHED shows underneath the AC ESS / DC ESS
When does the TR voltage / current value show in amber?
Why is the TR label in amber? White?
Voltage is below 25 V or above 31 V
Current is 5 A or less
Label amber if either of the above values is amber.
Label white if powered.
When will the GEN, EMER GEN, EXT PWR, APU or STAT INV voltage / frequency indications turn amber?
When will the GEN load indication turn amber?
Voltage: outside 110-120 V
Freq: outside 390-410 Hz
GEN load: above 100%
What 3 reasons might the IDG label be amber?
Why would the IDG number be amber?
- Outlet temp overheat
- Lo oil press
- Disconnection
Number amber:
* FADEC powered but engine off
Why would the IDG temp flash green? amber?
DISC amber?
LO PR amber
Flashing green: advisory 147-180ºC
Amber: over 180ºC
Disconnection
Low oil pressure
Where would GALLEY SHED appear on the ECAM?
Bottom centre of the ECAM ELEC SYS page
