Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

M11 > 11.6 elec power > Flashcards

11.6 elec power Flashcards

1
Q

where is electrical heating used

A

galleys, anti ice, water, cockpit windows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does the electrical power system consist of

A

generation, distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the electrical generation subsystems

A

AC/DC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the 3 different DC power sources on modern aircraft

A

DC battery, DC ext power, DC generators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is an aircrafts battery used to supply

A

emergency power, APU starter motor power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what type of battery is the main battery

A

nickel cadmium type

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what power does the main battery supply

A

24v DC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

whats the EPU

A

external power unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

whats the power source during flight

A

engine driven generators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how many AC generators does each engine have

A

one or more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

does the aircraft battery provide power in flight or ground

A

ground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

batteries provide power by converting what

A

chemical energy into electrical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

in an emergency how long will the battery supply power for

A

30 minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how are batteries vented

A

pipes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

whats used to prevent reverse flow in the ventilation system on ground

A

non return valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why is copper lockwire used to secure the battery connector

A

can quickly disconnect without wire cutters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the 2 types of aircraft main battery

A

Ni-Cd, lead-acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

during charging what is the individual cell voltage

A

1.5v

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

during discharge what is the individual cell voltage

A

1v

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

when are workshop checks carried out on batteries

A

2000 operating hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is one of the most major problems with batteries

A

thermal runaway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the 2 basic ways of charging batteries

A

constant voltage, constant current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what batteries is constant voltage charging method generally used on

A

lead-acid batteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what type of batteries use the constant current charging method

A

Ni-Cd batteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

in a battery test how long must a battery provide all necessary power for if failure occured

A

30 mins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

in battery tests what capacity do batteries require

A

80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what are the 2 different methods used to recharge NI-cd batteries

A

28v from DC VIA TRUs, separate battery charging unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what do AC powered aircraft require to be installed

A

battery charging unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

why dont we usually charge batteries from ground power

A

can easily overcharge batteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what does MFD stand for

A

multi function display

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what battery parameters are shown on the cockpit display

A

voltage, current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

when disconnecting a battery from an aircraft what lead do you disconnect first

A

negative lead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

when installing a battery to an aircraft what lead do you install last

A

negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

list the advantages of lithium ion compared to Ni-Cd batteries

A

high voltage/current, improved power quality, recharge quickly, less weight, compact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what stages are lithium ion batteries charged in

A

constant current, balance, voltage source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

lithium ion batteries have a fail safe feature that cuts the circuit out at what voltage

A

3-4.2v per cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

lithium ion cells cannot be charged safely below

A

0 degrees celcius

38
Q

what are the 3 different sources of DC power

A

DC battery, external, DC generator

39
Q

what type of battery is a DC battery

A

nickel cadmium

40
Q

what voltage does a DC battery supply

A

24v DC

41
Q

how many DC engine driven generators are there per engine

A

1

42
Q

how are DC batteries cooled

A

duct air or internal fan

43
Q

what are DC battery cores made from to prevent high altitude deformation

A

molybdenum disulphide

44
Q

a DC supply needs to provide constant voltage in what 3 conditions

A

engine speed change, no loads/full loads, share loads with generators

45
Q

what does the average DC starter generator weigh

A

10kg

46
Q

what is the normal RPM range for DC batteries

A

7000 - 12000 RPM

47
Q

what methods are used to attach AC and DC generators to engines

A

flange mounting, manacle ring

48
Q

where is the generators direction on rotation shown

A

on ident plate

49
Q

what is the purpose of a TRU

A

transfrom AC voltage to a DC voltage

50
Q

what does a parallel system consist of

A

two or more generators connected to a common power bus

51
Q

what does PPDS stand for

A

parallel power distribution system

52
Q

what are all relays controlled by

A

GCUs

53
Q

what are the advantages of parallel DC operation

A

TRUs loaded with average current, no DC bus lost when TRU fails

54
Q

when is the main DC power isolated

A

when a TRU fails

55
Q

what does the essential power distribution consist of

A

AC and DC part

56
Q

how does the systems know when an engine has started

A

the engine RPM is higher than the starter motor can reach

57
Q

what does airbus use for electronic controls in the cockpit

A

ECAM

58
Q

what does boeing use for electronic controls in the cockpit

A

EICAS

59
Q

on the elec sys control panel how many controls does each generator have

A

1 with an ON, OFF, RESET

60
Q

what are the 3 sources for AC power

A

AC generators, static inverters, rotary inverters

61
Q

what is the power of AC electrical power on aircrfat

A

400Hz 115/200 V

62
Q

in a rotating field alternator the rotating magnetic field can be

A

permanent magnet, DC wound coils

63
Q

in the rotating field alternator is there an electrical connection between the rotor and stator

A

no, only magnetic

64
Q

what is voltage proportional to

A

speed

65
Q

in AC power is rotational speed of the rotor increases what also increases

A

induced EMF

66
Q

the frequency of the alternating output of a generator is directly proportional to what

A

rotational speed of rotor

67
Q

how are AC generators output kept at a constant speed

A

by using a constant speed drive

68
Q

in the internal oil circuit what is the oil used for

A

hydraulic fluid for motor pump, cooling, lubrication

69
Q

in the external oil circuit what is the oil cooled by

A

oil cooler

70
Q

what 2 ways is the CSD monitored in

A

by circuits, by indicators

71
Q

what are the 2 CSD temp indicators

A

absolute oil temp, rise in temp

72
Q

what is the only consequence of under speed AC CSD

A

stops generator delivering correct frequency

73
Q

when disconnecting the CSD what do you check on the ECAM, EICAS displays

A

voltage and freq is 0

74
Q

when must disconnect resets be carried out on the CSD

A

on the ground

75
Q

why must the CSD be reset before engine starts

A

prevent damage to the IDG

76
Q

to reset the CSD how long must the button be held from and how often

A

3 seconds held for and no more than once every 60 seconds

77
Q

what does IDG stand for

A

integrated drive generator

78
Q

what does the IDG do

A

create AC power

79
Q

whats the frequency of aircrafts electrical supplies

A

400 Hz

80
Q

what are the 2 basic types of inverters

A

rotary, static

81
Q

what is a GCU

A

generator control unit

82
Q

what are the 3 functions of the GCU

A

regulation, protection, switching

83
Q

what does the GCU regulate

A

generator output

84
Q

AC generation systems have what 3 basic forms

A

non-parallel, parallel, frequency wild

85
Q

what form of AC generator system is the variable speed constant frequency

A

frequency wild generator

86
Q

are non parallel or parallel systems more complicated

A

parallel more complicated

87
Q

on DC powered aircraft where is AC power derived from

A

static inverters

88
Q

what is a CT

A

current transformer

89
Q

when cables pass through a current transformer, is there a physical connection between the cable and transformer

A

no

90
Q
A

M11 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions