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WorksheetsBell 412 - ATA 24 - Electrical
Total questions: 67
Worksheet time: 2hrs 41mins
Name
Class
Date
1.
In principal, how many basic electrical systems can be found in B412 helicopters?
a)
2
b)
3
c)
5
2.
Electrical systems of B412 principally differ ________________________
a)
in operability of emergency load switch
b)
in basic voltage used (28 vs 26,5 VDC)
c)
in basic system design (DC vs. AC)
3.
On early B412 models, the one-switch load shedding is ____________
a)
possible
b)
not possible
c)
- - -
4.
B412 DC electrical system provides _______________
a)
24 and 28 V only
b)
5, 26,5 and 28 V
c)
5, 24 and 28 V
5.
B412 AC electrical system provides _______________
a)
28 and 115 VAC
b)
26,5 and 115 VAC
c)
115 VAC only
6.
The primary B412 electrical power is _______________
a)
26,5 VAC
b)
24 VDC
c)
28 VDC
7.
The secondary B412 electrical power is _____________
a)
26,5 and 115 VAC
b)
28 VDC
c)
24 VAC
8.
B412 AC electrical system runs at _________________
a)
115 Hz
b)
400 Hz
c)
28 Hz
9.
Basic aircraft battery is a ____________ battery
a)
Ni-Cad
b)
Lead-Acid
c)
Ni-Mh
10.
Locate inverters
a)
6
b)
8
c)
1
11.
Locate GCUs
a)
6
b)
5
c)
4
12.
Locate GPU receptacle
a)
2
b)
3
c)
1
13.
Locate start relays
a)
2
b)
7
c)
8
14.
Locate battery relays
a)
1
b)
5
c)
4
15.
Locate GPU relay
a)
2
b)
3
c)
6
16.
Battery is normally charged by __________________
a)
STG 1
b)
STG 2
c)
both STGs
17.
The B412 DC system supplies 5VDC __________________________
a)
cockpit and cabin lights
b)
cabin lights only
c)
instrument lights
18.
Isolation of the two identical electrical systems (SYS1 and SYS2) is assured for by ____________
a)
isolation relays
b)
reverse flow capacitors
c)
diodes
19.
The emergency load switch is located ____________________
a)
central pedestal
b)
instrument panel
c)
overhead panel
20.
The emergency load switch is ____________________
a)
installed in all B412, but only operable in helicopters from s/n 33108 on (some canadian CAA exceptions possible)
b)
installed in all B412, but only operable in early helicopters up to s/n 33107
c)
installed only in helicopters with s/n 33108 and on
21.
STGs as installed on standard B412s are ________________
a)
unrestricted at 200 A
b)
derated to 150 A, but capable of 200 A
c)
rated at 150 A max
22.
Under normal circumstances, each STG supplies power directly to _______________________
a)
main bus only
b)
main bus and both non-essential buses
c)
both main buses and one non-essential bus
23.
Essential buses are fed from ________________________
a)
STGs directly
b)
main buses
c)
emergency busses through emergency power switches
24.
Emergency buses are fed from _________________
a)
main buses only
b)
STGs directly and from battery
c)
main buses and from battery
25.
In case of one STG failure (any reason), both non-essential buses _______________
a)
are automatically disconnected, power to non-essesntial buses cannot be restored under such circumstances
b)
must be manually disconnected by moving the "NON-ESNTL BUS" switch to OFF position
c)
are automatically disconnected, power to non-essential buses may be restored by moving the NON-ESNTL BUS to "override" position
26.
Both generators usually work in _______________________
a)
series
b)
parallel
c)
independently of each other
27.
In order to start the engine, the GEN switch must be set to __________________
a)
ON
b)
RESET
c)
OFF
28.
One of the conditions that must be met to connect the generator to the electrical system is:
a)
Battery must be disconnected from the system
b)
N2 speed must be over 71%
c)
The voltage on the output of the generator must be more than that on corresponding main bus
29.
Failure of one generator: The GCU commands the corresponding ____________ to trip off
a)
generator relay
b)
starter relay
c)
battery relay
30.
DC voltmeter indicates voltage of corresponding __________________
a)
emergency bus
b)
generator shunt
c)
essential bus
31.
Load meter(s) / ammeters indicate current through corresponding ________________
a)
emergency bus
b)
generator shunt
c)
main bus
32.
DC GENERATOR caution comes on when _____________________
a)
GCU senses higher voltage on generator output than on main bus
b)
generator is disconnected from the main bus
c)
generator is overheating
33.
GCUs are maintaining loads of both generators within __________ from each other when these are operating in parallel
a)
20 amps
b)
35 amps
c)
50 amps
34.
GCU controls the generator (maintains output at 28V) through ________________
a)
modifing the field energizing (excitation) current of each generator
b)
modifying the shunt resistance
c)
modifying the generator rotational speed
35.
Generators temperatures _______________________
a)
are monitored with a temperature switch
b)
are monitored with a temperature transducer
c)
are not monitored
36.
Standard battery on newer helicopters is __________________ battery
a)
19 cells lead-acid type
b)
20 cells Ni-Cad type
c)
19 cells Ni-Cad type
37.
Battery _________________________ to the battery bus
a)
is permanently connected
b)
connects through 1 battery relay
c)
connects through 2 battery relays
38.
Battery is connected _________ to __________ and from there it connects to the DC system through ___________________
a)
permanently - battery bus - 2 battery relays
b)
through a battery relay - shedding bus - one battery relay
c)
permanently - battery relay - battery bus
39.
Under normal circumstances, when both generators are supplying power to the DC system, __________________
a)
battery relay 1 is automatically de-energized (open)
b)
battery relay 2 is automatically de-energized (open)
c)
both battery relays are energized (close)
40.
Battery bus switch magnetical retention is used for ____________ position(s)
a)
ON
b)
OFF
c)
ON and OFF
41.
The "BATTERY" caution will be ON when _____________________
a)
one of the battery relays is open
b)
both battery relays are open
c)
both battery relays are in the same position (open or close)
42.
Battery temperature ______________ monitored
a)
is
b)
is not
c)
- - -
43.
The BATT TEMP light on the CWP is ________________
a)
amber caution
b)
red warning
c)
amber warning
44.
Battery interlock relay __________________
a)
controls both Battery Bus switches
b)
controls Battery bus switch 2 only
c)
controls Battery bus switch 1 only
45.
Invertors are supplied power from ________________
a)
main buses only
b)
essential buses
c)
emergency buses
46.
How many AC buses in total (SYS1+SYS2) are there in a B412 helicopter?
a)
6
b)
4
c)
3
47.
How many 115 VAC buses in total (SYS1+SYS2) are there in a B412 helicopter?
a)
3
b)
2
c)
1
48.
Early helicopters __________________ equipped with emergency AC buses
a)
were
b)
were not
c)
- - -
49.
Under normal conditions, INV 1 supplies power to ____________________
a)
No. 3 115 and 26,5 VAC buses
b)
No. 1 and 2 115 and 26,5 VAC buses
c)
All AC buses
50.
Under emergency conditions, INV 1 supplies power to ______________________
a)
All AC buses
b)
No. 1 and 2 115 and 26,5 VAC buses
c)
Emergency buses on later helicopters
51.
In case of one invertor failure, the other invertor supplies power to
a)
All AC buses
b)
No. 1 and 2 115 and 26,5 VAC buses
c)
Emergency buses on later helicopters
52.
AC voltmeters are reading voltage from ______________________
a)
No 1 and No 2 26,5 VAC buses
b)
No 1 and No 2 115 VAC buses
c)
No 3 115V and No 3 26,5 VAC buses
53.
When the EMER LOAD switch is moved over to EMERG LOAD position ______________
a)
both invertors are cut-off
b)
INV 2 is cut-off
c)
INV 1 is cut-off
54.
Which of the three symbols indicate a CB of a consumer powered from the emergency bus?
a)
A
b)
B
c)
C
55.
Which of the three symbols indicate a CB of a consumer powered from the essential bus?
a)
A
b)
B
c)
C
56.
Which of the three symbols indicate a CB of a consumer powered from the non-essential bus?
a)
A
b)
B
c)
C
57.
Can the engine no.1 be started from external power source with dead or weak battery in the helicopter?
a)
anytime
b)
only when the optional TB for such cases was applied
c)
That is impossible
58.
With the NON-ESSENTIAL bus switch in the NORM position __________________
a)
non-essential buses receive power in any case
b)
non-essential buses receive power from first generator brought online
c)
non-essential buses will only receive power after both generators are brought online
59.
When one of the two generator fails in-flight, _________________
a)
non-essential buses continue to receive power from the remaining generator irrespective of the NON-ESSENTIAL bus switch position
b)
non-essential buses are automatically cut-off, but the pilot may reconstitute power supply to non-essential buses by switching the NON-ESSENTIAL bus switchto MANUAL position
c)
non-essential buses are automatically cut-off only if the NON-ESSENTIAL bus switch is in MANUAL position
60.
Starter switch should be disengaged at ________________ speed
a)
55% N2
b)
55% N1
c)
71% N1
61.
Second engine shall NOT be started with the first engine operating below ____________ speed
a)
55% N2
b)
55% N1
c)
71% N1
62.
The best engine speed to start the other engine is __________
a)
85% N2
b)
55% N1
c)
85% N1
63.
If, for any reason, the DC system voltage exceeds the corresponding generator output voltage ______________
a)
The GCU disconnects the generator to prevent reverse flow current
b)
The GCU increases the generator's output voltage
c)
The GCU commands the generator to increase its output current
64.
The GEN OVHT caution is triggered when the generator temperature is _________
a)
68 C or higher
b)
71 C or higher
c)
155 C or higher
65.
Essential bus failure is indicated by________________
a)
high DC voltage readings
b)
0 DC voltage reading of corresponding voltmeter
c)
low load readings
66.
Emergency buses are _______________________
a)
not interconnected
b)
interconnected through a CB
c)
interconnected - hard wired
67.
One of the emergency bus failure indications may be ________________
a)
N1 indication failure
b)
N2 speed indication failure
c)
ITT or eng oil temp indications failure
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