Electrical Flashcards
Electrical 3 areas:
Components, Controls and indications, Power supply priority
Electrical system AC three phase 115/ 200 v AC DC
28v
If all electrical power sources inoperative,
A STAT INV will convert battery DC to AC power
Priority order for AC BUS 1 / AC BUS 2 – highest priority
Corresponding Engine Generators, APU generator / external power A, external power B, opposite engine generator
APU battery is reserved for
APU starting
All of circuit breakers on aircraft are located on
The electronic equipment bay
IDG power is
AC system
IDG = GEN (on ECAM) driven constant speed by
Integrated drive, supply electrical system with up to 115 kVa of three phase 115/200v power at 400Hz
IDG – power normal electrical components at 115v and higher load such as hydraulic pumps at
200v
APU GEN =
GEN 1 = 2
Generator Control Unit GCU
Controls generator output, controls generator priority, protects generator and network, supplies indications and warnings
Overhead switches control
Engine driven generators, their respective GCU and GLC Generator Line Contactors
If GLC opens with Gen ON
FAULT displayed
If IDG disconnected
Only AzulTec reconnects on ground
Do not disconnect IDG if
Engine not running or windmilling
ECAM Low oil pressure IDG inhibited low
N3 less than 52% and N3 less than 52%
APU doesn’t supply electrical system powered by
Engine Driven Generators
When aircraft on ground, engine not running, an amber FAULT on GEN 1 or 2 sw means
That generators are not operating, amber FAULT is normal on ground
When IDG 1 or IDG2 malfunctions, it can be disconnected from the engine through the
Use of the respective IDG pb
AC Power system:
AC power busses and Bus Tie Contactor, electrical contactor management unit ECMU, no break power transfer control NBPTC, controls and indicators
ECMUs electrical Contactor Management Units are computers that enable electrical system
to reconfigure itself depending on availability of various power sources
Synchronization may take up to
15 seconds for APU Gen with GPU
The LAND Recovery AC BUS is powered by Emergency Operations when
LAND Recovery pb sw is ON
If AC BUS 1 fails, the AC ESS BUS
is powered by AC BUS 2
Bus TIE pb sw is normally in
AUTO position
DC power systems are
Transformer rectifiers, aircraft batteries, static inverter, controls and indicators
Transformer rectifiers convert
115v AC to 28v DC
Fault light on BAT1 (2) pb sw illuminates when
Charging current for corresponding battery is outside limits
A static inverter transforms DC power int
AC power which is supplied to part of AC ESS BUS
APU TR voltage indication on ECAM ELEC DEC page remains green,
Even if abnormal, during the engine start
HOT BUS 1 and HOT BUS 2 are permanently
Connected to BAT 1 and 2 respectively
When DC BUS 1 / 2 are not powered, indication on ECAM ELEC DC page
Is amber
DC LAND RCVRY BUS is normally
Supplied by DC ESS BUS
When aircraft on ground, if EXT A or EXT B pb sw shows AVAIL illuminated in green
external power is connected, but not in use.
Aircraft ground power connectors are located
Aft of the nose wheel
MAINT BUS sw is used to power only the electrical systems used
for ground servicing.
If both AC BUS 1 and AC BUS 2 are lost and both engines lose power,
The RAT automatically extends. RAT powers EMER GEN through green hydraulic system
When RAT is being deployed EMER GEN light will indicate
FAULT in red momentarily
EMER GEN TEST pb on EMER ELEC panel is used to
Test the Emergency Electrical system, for maintenance purposes only
When in use, emergency generator is powered by
The green hydraulic system
Preliminary cockpit preparation – aircraft not electrically supplied for 6 hours or more, check BAT 1, 2, APU BAT voltages for greater than
25.5v
To check battery voltage for Bat 1, 2, APU bat, respective BAT switch must be
Switched off before checking voltage
When disconnecting IDG when prompted by ECAM, IDG pb should be
Pressed for no more than 3 seconds
When the electrical emergency configuration fault occurs, the lower ECAM, Captain’s ND and FO’s
PFD and ND displays are lost.
