Electrics Flashcards
Which cockpit lighting is available during an emergency electrical situation?
Right side dome light main panel flood lights (left two columns only) and the standby compass light.
What is the function of the static inverter?
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.
How many types of circuit breakers has the aircraft?
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).
Can you reconnect an IDG in flight?
No.
AC Power (115v) can be provided by which power sources?
Two engine generators one APU generator and one external power source.
What is the order of priority for the different generators?
Engines external power APU.
If the battery voltages are below the minimum how do you charge them?
I have to check that the BAT pushbuttons are on and switch the external power on.
When does the RAT automatically deploy?
Electrical power to both AC BUS #1 & #2 is lost and the aircraft speed is above 100 knots.
Is it possible to connect the engine driven generators in parallel?
No.
What does the blue EXT PWR ON light mean?
External power is supplying the aircraft electrical systems.
After IDG disconnection why do you get a GALLEY SHED indication in the SD?
It is a reminder that the main galley has been shed automatically following the loss of one generator.
If both engine generators are powering the system and one subsequently fails are any busses unpowered?
No but some loads are shed in both main galleys.
What is the purpose of the Ground and Auxiliary Control Power Unit (GAPCU)?
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.
Where is the ground power connector?
The ground power connector is near to the nosewheel on the right side of the fuselage.
What occurs in case of a TR fault?
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.
Having started the APU with external power connected how can you get the APU generator to power the electrical system?
By pushing the EXT PWR Pb thus disconnecting the external power.
What powers the emergency generator?
The blue hydraulic via the RAT.
You enter a dark cockpit what action is necessary before checking the battery voltages?
You have to check that both batteries are off.
What is the purpose of the Transformer Rectifiers (TR’s)?
Two main Transformer Rectifiers TR 1 and TR 2 supply the aircrafts electrical system with up to 200 amperes of DC current. A third identical TR the ESS TR can power the essential DC circuit from the emergency generator if the engine and APU generators all fail or if TR 1 or TR 2 fails.
What are the main functions of the Generator Control Unit (GCU)?
Controls the frequency and voltage of the generator output and protect the network by controlling the associated generator line contactor (GLC).
Which bus supplies the AC ESS BUS?
The AC ESS BUS is normally supplied from the AC BUS 1 it may be supplied be AC BUS 2 through the AS ESS FEED pb.
What is the capacity of the main batteries?
Two main batteries have a capacity of 23 ampere-hours each.
BAT 1 (2) pb (ELEC Panel)
- Auto
- OFF
- FAULT Light
Auto:
The battery charge limiter automatically closes/opens the corresponding battery line contactor. The batteries are connected to the DC BAT BUS in the following cases:
• APU starting until N < 95%. (limited to 3 min when the emergency generator is running)
• Battery voltage < 26.5 V (battery charge).
• Loss of AC BUS 1&2 when below 100 knots (EMER GEN not supplying).
OFF:
The battery charge limiter is not operating: the battery line contactor is open.
FAULT Light:
The charging current for the corresponding battery is outside limits. In this case the battery contactor opens.
IDG 1 (2) pb (guarded) (ELEC Panel)
- FAULT Light
Switch spring loaded out.
Do not hold > 3 sec.
Do not disconnect when engine not windmilling.
FAULT Light:
- IDG oil outlet overheats (above 185°C), or
- IDG oil pressure is low (inhibited at low engine speed: N2 below 14 %)
LT extinguishes when the IDG is disconnected.
GEN 1 (2) pb (ELEC Panel)
- ON
- OFF
- FAULT Light
ON:
Generator line contactor closes if electrical parameters are normal.
OFF:
Generator line contactors open. The fault circuit is reset.
FAULT Light:
- The generator control unit (GCU) trips it.
- Line Contactor open with the GEN pb selected ON
APU GEN pb (ELEC Panel) - ON - OFF - FAULT Light
ON:
Line contactor closes if parameters are normal and the EXT PWR line contactor is open.
OFF: Line contactor opens. The fault circuit is reset.
FAULT LT:
- The generator control unit (GCU) trips it.
- Opening of the line contactor (except if the APU GEN pb is selected OFF). The light is inhibited when APU speed is too low or if the APU GEN line contactor opens after EXT PWR or ENG GEN takes over.
BUS TIE pb
(ELEC Panel)
- AUTO
- OFF
AUTO:
The bus tie contactors (BTCs) open or close automatically.
OFF:
Both bus tie contactors open.
AC ESS FEED pb
(ELEC Panel)
- NORMAL
- ALTN
- FAULT Light
NORMAL:
The AC ESS BUS is supplied from AC BUS 1. It is automatically supplied by AC BUS 2, when AC BUS 1 is lost.
ALTN:
Comes on when manually selected. The AC ESS BUS is supplied from AC BUS 2.
FAULT LT:
AC ESS BUS is not supplied.
GALY & CAB pb
(ELEC Panel)
- AUTO
- OFF
- FAULT Light
AUTO:
Main galley, secondary galley and in-seat power supply are supplied.
The main galley and in-seat power supply are shed automatically when:
- In flight: only one generator is operating.
- On the ground: only one engine generator is operating. (Except APU or EXT power.)
OFF:
The main galley, secondary galley and in-seat power supply are not supplied.
FAULT LT:
When the load on any generator is more than 100% of rated output.
EXT PWR pb
(ELEC Panel)
- AVAIL Light
- ON Light
AVAIL light comes on green if:
- External power is plugged in, and
- External power parameters are normal.
Pressed momentarily:
Opens/Closes the external power line contactor. The ON light comes on blue when closed.
COMMERCIAL pb
(ELEC Panel)
- ON
- OFF
ON: All aircraft commercial electrical loads are supplied: - Cabin and cargo lights - Water and toilet system - Drain mast ice protection - Galley - Passengers' entertainment - Semi-automatic cargo loading (if installed)
OFF:
Switches off all aircraft commercial electrical loads.
MAN ON pb (guarded)
(EMER ELEC PWR panel)
- AUTO
- Pressed
AUTO:
RAT deploys when
- AC BUS 1&2 is not electrically supplied and speed >100 knots.
Pressed:
Manual RAT extension.