ATA 24: Electrical Flashcards
The Main AC generators are ______ ______ each with a nominal output of ______ kVA.
Two Main AC generators are engine driven each with a nominal power ouput of 115 kVA.
The Auxiliary Power Unit (APU) AC generator
has a nominal power output of ______ kVA.
The APU AC generator has a nominal power output of 115 kVA.
The Emergency Generator is a ______ ______ ______ ______ (CSM/G) with a nominal power output of ______ kVA.
It is driven by the ______ system.
The Emergency Generator is a Constant Speed Motor/Generator (CSM/G) with a nominal power output 8.6 kVA.
Hydraulically driven by the GREEN system
The Static Inverter is fed by ______ ______ and operates on the ______ when the ______ is inoperative.
The Static Inverter is fed by two batteries and operates on the ground when the CSM/G is inoperative.
Describe the Ground Connectors - number and power output.
Two ground connectors
with an ouput of 90 kVA each
There are ______ main TRU’s (200A), ______ essential TRU (100A) and ______ TRU (100A) dedicated to the ______ ______ or ______ ______ ______.
There are two main TRU’s (200 A), one essential TRU (100 A), and one TRU (100 A) dedicated to the APU start or APU battery charging.
There are ______ batteries, each with a nominal capacity of 28v.
______ are used in ______ ______ during ______ deployment or when the ______ is not operating.
______ is dedicated to the ______ start.
There are three batteries, each with a nominal capacity of 28v.
Two are used in emergency configuration during RAT deployment or when the CSM/G is not operating
One is dedicated to the APU start.
Describe the AC Distribution Network
- Normal configuration: each ____ ____ ____ supplies its _____ AC BUS.
- AC ESS BUS is normally supplied from ____ ____ __
- Normal configuration: each engine-driven generator supplies its associated AC BUS.
- AC ESS BUS is normally supplied from AC BUS 1.
Describe the DC Distribution Network - Normal Configuration
-The normal DC system is split into two networks: DC BUS 1 in parallel with DC BAT BUS and DC BUS 2.
- Each DC network is supplied by its own Transformer Rectifier (TR).
Describe the DC ESS BUS
The DC ESS BUS is fed by the ___ ___ systematically for better segregation between DC 1 and DC 2.
The DC ESS BUS is fed by the ESS TR systematically for better segregation between DC 1 and DC 2.
What is the relationship between the batteries and HOT BUS Bar?
Two batteries are permanently connected to the two hot busses.
What is the third battery used for?
The third battery is dedicated to APU starting.
What is the Battery Charge Limiter (BCL) used for?
The Battery Charge Limiter (BCL) connect two batteries to the DC BAT BUS.
Describe what happens when a generator fails
If one generator fails, another will automatically take over.
If APU is operative, APU generator will take over.
If APU generator is not available, the other engine generator will take over.
What happens with a total loss of all main generators (engines still running)?
The emergency generator delivers 8.6 kVA of power and the GREEN hydraulic system is still powered by engine-driven pumps.
What happens in the case of total generator failure due to all-engines loss?
- The emergency generator delivers 3.5 kVA via the GREEN hydraulic system.
- It is powered by the RAT (otherwise the engine pump(s) if at least one engine is running).
- Batteries take over when slats are extended.
What happens with a single TR failure?
If one TR fails, the other will automatically take over its corresponding DC network via DC BAT BUS.
What happens with a double TR failure? (Two possible scenarios)
- TR 1 and 2: DC BUS 1 and DC BUS 2 are lost.
- TR 1 (or 2) and ESS TR: The remaining TR supplies DC BUS 1 + 2 and DC BAT BUS; the DC ESS BUS is lost.
How are the circuit breakers monitored?
By the CBMU (Circuit Breaker Monitoring Units) and a C/B page on the ECAM.
If external power is available and is within the power criteria for aircraft use:
(a) It will automatically close the bus tie contactor’s when connected by the ground crew
(b) The GREEN avail light will illuminate on the EXT PWR pb
(c) The bus tie Pb illuminates
(b) The GREEN avail light will illuminate on the EXT PWR pb
If during a normal flight, the BUS TIE Pb was depressed to off, what effect would this have on power to the busses?
(a) None
(b) All power would be lost and the batteries would power the aircraft until the RAT was up to speed
(c) AC ESS Bus will be lost and ALTN light on AC ESS FEED switch will illuminate
(a) None
If both engine generators are powering the system, and one subsequently fails, are any
busses unpowered?
(a) No, but some loads are shed in the galleys
(b) Only the AC ess. Shed bus
(c) Yes, those associated with the failed generator
(a) No, but some loads are shed in the galleys
What would cause the galley fault light to illuminate?
(a) When the flight attendants have all the coffee makers and ovens on at once
(b) When the main galley has shed
(c) When an overload is detected and auto shedding is not performed
(c) When an overload is detected and auto shedding is not performed
What is the function of APU GEN pb located on the overhead electrical panel?
(a) When on it connects APU generator to the electrical system when engines are running
(b) When selected to off the APU generator field is de-energised and if connected to the electrical system, disconnects
(c) Both A and B are correct
(b) When selected to off the APU generator field is de-energised and if connected to the electrical system, disconnects
If the normal source of power for the ESS AC Bus is lost, does another source of power automatically power the bus?
(a) Yes, only if NORMAL was selected on the AC ESS FEED Pb
(b) Yes, only if ALTN was selected on the AC ESS FEED Pb
(c) No, this is an action that must be accomplished by the crew
(a) Yes, only if NORMAL was selected on the AC ESS FEED Pb
Whilst the RAT is deployed in an emergency, the static inverter supplies the:
(a) AC ESS BUS and AC Ess Grnd
(b) AC ESS BUS and AC Ess Shed Bus
(c) AC ESS BUS only
(c) AC ESS BUS only
Electrical Contractor Management Unit (ECMU) function is:
a. control of AC and DC bus ties
b. TR contractors monitoring
c. automatic management and monitoring
c. automatic management and monitoring
Loss of one generator or TR:
a. results in the loss of the corresponding AC or DC bus
b. has no effect on flight management
c. requires to have the APU generator operational
b. has no effect on flight management
The minimum number of generators required to supply all the network (in a non-overload condition) is
a. one engine generator
b. one engine generator and the EMER generator
c. two generators
a. one engine generator
The emergency generator is powered by:
a. a Ram Air Turbine
b. the Static Inverter
c. the green hydraulic system when pressurized by engine 1 or 2 driven hydraulic pump or by Ram Air Turbine
c. the green hydraulic system when pressurized by engine 1 or 2 driven hydraulic pump or by Ram Air Turbine
An engine generator is driven:
a. at a ratio of 5:1 to engine speed
b. direct from the accessory gear box
c. by an Integrated Drive Generator (IDG)
c. by an Integrated Drive Generator (IDG)
Each engine generator supplies power to:
a. its assigned AC BUS in normal operation
b. the opposite side AC BUS in normal operation
c. only its assigned BUS in all cases
a. its assigned AC BUS in normal operation
The APU battery:
a. is dedicated to APU start only
b. may be used for Engine Start when the APU is not available
c. can be used as a backup for Battery One or Battery Two
a. is dedicated to APU start only
Normally which AC BUS supplies the ESS TR?
a. AC BUS 1
b. AC BUS 2
c. AC ESS BUS
a. AC BUS 1
When the Battery selector is in the #2 position, which of the following is true?
a. BAT 2 has been selected to start the APU
b. BAT 2 voltage can now be read in the voltage indicator window
c. APU BAT voltage can now be read in the voltage indicator window
b. BAT 2 voltage can now be read in the voltage indicator window
In flight, APU not running, an engine generator has failed, which source is supplying the the corresponding AC BUS?
a. the Static Inverter
b. the AC BUS is lost
c. the other side engine generator
c. the other side engine generator
Two Electrical Contactor Management Unit (ECMU) provide:
a. control of TR contactors
b. AC and DC contactors control and monitoring except for TR contractors
c. AC and DC contactors control and monitoring except for TRs which have their own control, gallery shedding and no break power transfer
c. AC and DC contactors control and monitoring except for TRs which have their own control, gallery shedding and no break power transfer