23 June 2011 6077AC Electrical Systems Safety – Capstone Assessment

Family Name .................................................................................
Given Name ...................................................................................
Student Number ...........................................................................
Centre ............................................................................................
Signature .......................................................................................
23 June 2011
6077AC Electrical Systems Safety – Capstone Assessment
Time allowed – Three hours plus Ten minutes reading time
29 Pages in this Question Booklet
All Questions to be attempted
TOTAL MARKS AVAILABLE =100
Aids to be supplied by college
• None
Aids to be supplied by student
• Australian/New Zealand Wiring Rules AS/NZS
3000:2007 (AMDT No 1 – July 2009)
• Service and Installation Rules of NSW – NSW
Dept. of Water & Energy.
• Australian/New Zealand Standard Electrical
Installations - Selection of Cables AS/NZS
3008.1.1:2009.
Section
Possible
Marks
A
20
B
20
C
45
D
15
Total
100
Achieved
Marks
• Students own marginal notes, indexing and formal amendments may be included in the
above regulatory publications.
• Pen, pencil, eraser, rule and calculator.
Instructions to Student
• Mobile phones are to be turned off and removed from your person. You cannot
access a mobile phone during this test.
• All questions to be answered in the space provided on this examination paper.
Answers to Section A – multi-choice questions, are to be answered on the sheet attached
to this examination paper.
• You are not to use any other reference book in this examination.
• The whole of this paper is to be handed to the teacher upon completion.
Aids permitted where indicated:
Standard
Dictionaries
Bilingual
Dictionaries
Technical
Dictionaries
Programmable
Calculators
Non-programmable
Calculators
Electronic
Devices
No
No
No
No
Yes
No
- 2 -
SECTION A – (20 Marks)
INSTRUCTIONS: Select the best answer for the following statements and place an ‘X’ in
the appropriate box on the Answer Sheet attached to this examination paper. Each correct
answer is worth one (1) mark.
QUESTION 1
(1 Mark)
The maximum permissible disconnection time for a 40 Amp type ‘C’ circuit breaker
protecting a permanently installed motor wired via an isolator is:
(a)
400 milliseconds
(b)
0.4 hour
(c)
1.0 hour
(d)
5.0 seconds
QUESTION 2
(1 Mark)
A customer complains that when they plug an appliance into a particular socket outlet, the
RCD immediately trips. Of the following options, the most likely cause of the fault would
be:
(a)
a transposition of the neutral and earth conductors at the socket outlet
(b)
a transposition of the active and neutral conductors at the socket outlet
(c)
an open-circuit earth conductor
(d)
an open circuit active conductor
QUESTION 3
(1 Mark)
A circuit is wired with 2.5 mm2 TPS twin and earth cable that is clipped to the side of the
ceiling joists in a domestic installation where bulk thermal insulation is installed. This circuit
would be classified as:
(a)
likely to be disturbed
(b)
enclosed in thermal insulation
(c)
totally surrounded by thermal insulation
(d)
partially surrounded by thermal insulation
QUESTION 4
(1 Mark)
The minimum size copper earth conductor for a 3-phase industrial oven supplied by 25mm2
copper active conductors is:
(a)
4 mm2
(b)
6 mm2
(c)
10 mm 2
(d)
25 mm2
6077AC MY2011
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- 3 -
SECTION A – (Cont’d)
QUESTION 5
(1 Mark)
The magnetic mechanism of a thermal-magnetic circuit breaker:
(a)
operates by heating a bi-metal strip.
(b)
operates on long time overloads only.
(c)
has a time response suitable for overload protection.
(d)
has a time response suitable for short-circuit protection.
QUESTION 6
(1 Mark)
When single-insulated wire is installed in ducting that has a removable lid:
(a)
the cables must be taped together and held in position
(b)
the lid must be held in position with cable ties
(c)
building wire is not permitted in a duct which has a lid
(d)
the lid shall not be removed without a special tool if the duct is readily accessible
QUESTION 7
(1 Mark)
A low resistance measured between neutrals of different circuits indicates the probability of:
(a)
an open circuit neutral
(b)
a short circuit between neutral and earth
(c)
a short circuit between active and earth
(d)
interconnection between the two circuits
QUESTION 8
(1 Mark)
The primary function of over-current circuit protection in an installation, is to:
(a)
reduce the effect of electric shock.
(b)
prevent electric shock.
(c)
protect the circuit conductors from damage due to overheating.
(d)
protect the appliance from damage due to overheating.
QUESTION 9
(1 Mark)
The International Protection Rating (IP) indicates the degree of protection of electrical
equipment enclosures against penetration by:
(a)
hazardous gases
(b)
solid objects and water
(c)
unauthorized persons
(d)
flammable liquids and gases
6077AC MY2011
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- 4 -
SECTION A – (Cont’d)
QUESTION 10
(1 Mark)
The maximum value of current that may flow in the electrical system during a short circuit is
the:
(a)
let through value of current.
(b)
cut off current.
(c)
prospective short circuit current.
(d)
trip or fusing current.
QUESTION 11
(1 Mark)
When testing the earth continuity it is recommended that:
(a)
protective earth conductors be disconnected from all appliances
(b)
protective earth conductors be disconnected from water heaters
(c)
an insulation resistance tester on the 250V range is used
(d)
an insulation resistance tester on the 500V range is used.
QUESTION 12
(1 Mark)
The NSW Service and Installation Rules require that the original notification of the results of
all compliance tests, for a completed electrical installation, must be submitted to the
appropriate persons/bodies within:
(a)
48 hours
(b)
1 week
(c)
14 days
(d)
1 month.
QUESTION 13
(1 Mark)
The term ‘discrimination’ as applied to circuit protection means:
(a)
the circuit protection on the main switchboard should be the first to operate.
(b)
the fuse or circuit breaker with the highest fault current rating should operate first.
(c)
the circuit protective device closest to the fault or over-current should operate before
any upstream devices.
(d)
the circuit protection should be able to distinguish between a short circuit to earth and
a short circuit between live conductors.
6077AC MY2011
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- 5 -
SECTION A – (Cont’d)
QUESTION 14
(1 Mark)
What is the term used in AS/NZS 3000 to describe the maximum demand current for which
a circuit is designed:
(a)
IB
(b)
IN
(c)
Iz
(d)
Isc
QUESTION 15
(1 Mark)
The minimum IP rating required for a socket outlet installed in a bathroom within the area
designated as zone 0 is:
(a)
IPX4
(b)
IPX7
(c)
1P56
(d)
socket outlets are not permitted in Zone 0
QUESTION 16
(1 Mark)
The insulation resistance tester used to test a three-phase 400 Volt sub-main must be tested
by applying a DC voltage of:
(a)
250V
(b)
500V
(c)
750V
(d)
1000V
QUESTION 17
(1 Mark)
What is the minimum depth of cover of a Category A underground wiring system which is to
be located below a 150mm concrete slab, and is located within the confines of a building:
(a)
300 mm below finished ground level
(b)
500 mm below finished ground level
(c)
600 mm below finished ground level
(d)
directly below the concrete slab
6077AC MY2011
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- 6 -
SECTION A – (Cont’d)
QUESTION 18
(1 Mark)
The colour coding used to identify a dry chemical powder fire extinguisher is:
(a)
red without colour stripe
(b)
red with white stripe
(c)
red with black stripe
(d)
blue without colour stripe
QUESTION 19
(1 Mark)
To comply with the requirements of AS/NZS 3000, the minimum size equi-potential
bonding conductor for bonding the water pipe, when the consumer main is copper 50 mm2,
3-phase and neutral, is:
(a)
4.0 mm2
(b)
6.0 mm2
(c)
16.0 mm2
(d)
50.0 mm2
QUESTION 20
(1 Mark)
A major hazard with confined spaces is:
(a)
difficulty in using tools
(b)
unable to stand upright when working
(c)
only one person can work at a time
(d)
flammable contaminants and oxygen depletion
6077AC MY2011
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- 7 -
SECTION B – (20 Marks)
INSTRUCTIONS: Answer the following questions in the spaces provided.
•
•
Use AS/NZS 3000:2007 to best answer each question.
Write clause numbers where required.
QUESTION 1
(2 Marks)
A circuit for a fixed or stationary cooking appliance incorporating an open cooking surface
must have a functional switch. Name three (3) examples of cooking appliances having an
open surface?
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
AS/NZS 3000 Reference (Clause number _______________ )
QUESTION 2
(2 Marks)
What is the maximum number of circuits that can be connected an individual RCD in a
domestic installation is:
__________________________________________________________________________
AS/NZS 3000 Reference (Clause number _______________ )
QUESTION 3
(2 Marks)
When is it necessary to provide protection for persons and livestock against injury from
mechanical movement of electrically actuated equipment?
(a) _________________________________________________________________ or
(b) _________________________________________________________________
_________________________________________________________________
AS/NZS 3000 Reference (Clause number _______________)
6077AC MY2011
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- 8 -
SECTION B – (Cont’d)
QUESTION 4
(2 Marks)
Specify the four (4) acceptable methods of protection against indirect contact.
(a)
________________________________________________________________
(b)
________________________________________________________________
(c)
________________________________________________________________
(d)
________________________________________________________________
________________________________________________________________
AS/NZS 3000 Reference (Clause number _______________)
QUESTION 5
(2 Marks)
Where recessed ELV halogen down-lights are installed, what precautions must be made to
minimise the temperature rise and prevent the risk of fire caused by heat at the rear of the
luminaire?
(a)
________________________________________________________________
________________________________________________________________
________________________________________________________________
(b)
________________________________________________________________
________________________________________________________________
(c)
________________________________________________________________
________________________________________________________________
(d)
________________________________________________________________
________________________________________________________________
AS/NZS 3000 Reference (Clause number _______________)
6077AC MY2011
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- 9 -
SECTION B – (Cont’d)
QUESTION 6
(2 Marks)
Where consumers mains are not protected on the supply side by short circuit protective
devices, the MEN link shall have a cross sectional area not less than that of the?
__________________________________________________________________________
AS/NZS 3000 Reference (Clause number _______________ )
QUESTION 7
(2 Marks)
When consumer mains have multiple active conductors connected in parallel (e.g. 2 per
phase), how is the size of the main earth conductor determined?
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
AS/NZS 3000 Reference (Clause number _______________)
QUESTION 8
(2 Marks)
At what location should the equipotential bonding conductor be connected to the metallic
water service?
__________________________________________________________________________
__________________________________________________________________________
AS/NZS 3000 Reference (Clause number _______________)
6077AC MY2011
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- 10 -
SECTION B – (Cont’d)
QUESTION 9
(2 Marks)
A 230 Volt final sub-circuit consists of a V75 rated multi-core cable and supplies a 25A nonRCD protected socket outlet within a commercial computer room. A 25A type ‘C’ circuit
breaker protects the circuit. Determine the maximum allowable fault-loop impedance, when
supply is available and the complete loop is tested.
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
QUESTION 10
(2 Marks)
Specify four (4) requirements for connecting the main earth conductor to an earth electrode.
(a) ________________________________________________________________
________________________________________________________________
(b) ________________________________________________________________
________________________________________________________________
(c) ________________________________________________________________
________________________________________________________________
(d) ________________________________________________________________
AS/NZS 3000 Reference (Clause number _______________)
6077AC MY2011
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- 11 -
SECTION C – (45 Marks)
INSTRUCTIONS: This section involves calculations. Show all necessary working in the
space provided, marks will be awarded accordingly. Write answers in the spaces provided.
QUESTION 1.
(5 Marks)
A small retail complex consisting of 4 shops at street level (350 m2 each) and 3 offices
(250 m2 each) on the first floor. All shops and offices have reverse cycle air conditioning,
light and power. Using average VA/m2 rates outlined in Appendix C of AS3000, determine
the maximum demand of the 400 Volt three-phase consumer mains for this commercial
installation.
Type of Occupancy
Load
Shops
Energy Demand
Area
Average
VA/m2
Demand
VA
Light and power
Air conditioning
Offices Light and power
Air conditioning
Total VA
Maximum Demand ______________ Amps per phase
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
6077AC MY2011
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- 12 -
SECTION C – (Cont’d)
QUESTION 2.
(5 Marks)
Calculate the maximum demand of a three-phase 230/400V sub-main to a non-airconditioned portion of a factory having the following load:
48 only triple 36 W fluorescent luminaires having a rating of 0.45 A each (3 circuits)
18 only 10 A double socket outlets (3 circuits)
2 only 3-phase 400 volt motor having full load current of 20 A per phase
2 only 3-phase 400 volt motors having full load current of 10 A per phase each
Load
group
Load description
Qty
Calculation
Demand Demand Demand
(Red)
(White)
(Blue)
Lighting
Socket outlets
400V - 20A motor
400V - 20A motor
400V - 10A motor
400V - 10A motor
Maximum
Demand
6077AC MY2011
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- 13 -
SECTION C – (Cont’d)
QUESTION 3.
(5 Marks)
Calculate the maximum demand of a three-phase 230/400V consumer main to a block of 21
town houses (units) each having following load:
28 only lighting points
6 only single socket outlets
16 only double socket outlets
6.9 kW 230V electric cook top
4.6 kW 230V electric oven
8
kW permanently connected air conditioner having full-load current of 16 A
4.6 kW 230V storage hot water service
Balance the load evenly over the three-phases.
Load
group
Load description
Qty
Calculation
Demand
(Red)
Demand
(White)
Demand
(Blue)
Lighting
Socket outlets
Electric cooktop
Electric oven
Air conditioner
Hot water service
Maximum
Demand
6077AC MY2011
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- 14 -
SECTION C – (Cont’d)
QUESTION 4.
(4 Marks)
A 400-volt, three-phase final sub-circuit in a non-domestic installation consists of three X90,
single-core, thermoplastic and sheathed copper conductors supplying a 100-ampere resistive
load. The circuit is enclosed in heavy-duty rigid thermoplastic conduit with no other
circuits. The conduit is buried in the ground having an ambient soil temperature of 25ºC and
has a top cover of 0.5 metre. Circuit protection is by way of HRC fuses and the distance
from the switchboard to the load terminals of the equipment is 70 metres.
Calculate the minimum permissible cable size if the voltage drop in this cable segment is not
to exceed 2.5%.
Voltage Drop Table No:
____________________________________
Conductor size:
____________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
6077AC MY2011
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- 15 -
SECTION C – (Cont’d)
QUESTION 5.
(7 Marks)
Calculate the voltage drop in each segment of a three-phase, 400-volt non-domestic
installation consisting of the following:
(a)
Consumer main:
Phases:
Maximum demand:
Route length:
Cable size:
Cable configuration:
Cable installation:
3
63 A
40 m
25 mm2
X90 single core thermoplastic and sheathed copper
conductors
The circuit is enclosed in heavy-duty rigid
thermoplastic conduit with no other circuits. Conduit is
buried in the ground having an ambient soil temperature
of 25ºC and has a top cover of 0.5 m
Voltage Drop Table No:
____________________________________
mV/A.m rating:
____________________________________
Volt drop:
____________________________________
____________________________________
(b)
Sub-main:
Phases:
Maximum demand:
Route length:
Cable size:
Cable configuration:
Cable installation:
6077AC MY2011
3
40 A
30 m
16 mm2
V90 single core thermoplastic and sheathed copper
conductors
The cables are clipped to the building structure in
trefoil formation and installed in single circuit
configuration, unenclosed in air
Voltage Drop Table No:
____________________________________
mV/A.m rating:
____________________________________
Volt drop:
____________________________________
 TAFE NSW
- 16 -
SECTION C – (Cont’d)
QUESTION 5.
(c)
(cont)
Final sub-circuit:
Phases:
Maximum demand:
Route length:
Cable size:
Cable configuration:
Cable installation:
1
20 A
25 m
2.5 mm2
V90 two-core and earth thermoplastic and sheathed
copper conductors
The cables are clipped to the building structure and
installed in single circuit configuration, unenclosed in
air
Voltage Drop Table No:
________________________________________
mV/A.m rating:
________________________________________
Volt drop:
________________________________________
________________________________________
Considering all three portions, does the final voltage-drop comply with the requirements of
AS/NZS 3000? Provide a reason why it does, or does not comply.
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
6077AC MY2011
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- 17 -
SECTION C – (Cont’d)
QUESTION 6.
(3 Marks)
The maximum demand current of a sub-mains in a non-domestic installation is calculated to
be 50 amperes. The selected cable is 4-core, non-armoured, X90 insulated and sheathed,
circular cable with copper conductors. Installation of the cable places is clipped directly to
an internal wall with four other similar circuits, touching in a single layer, open to the air,
and protected by 50 Amp circuit breakers.
Use AS/NZS 3008.1.1 to determine a suitable conductor size for the installation.
Multiple Circuits:
De-rating Table No:
Column No:
De-rating factor:
Minimum Current Carrying Capacity of the required
conductor:
Required conductor size:
Table No:
3(
)
Item No:
Table No:
Column No:
Conductor size:
Earth conductor:
Minimum earth conductor size:
Reference:
Coordination between conductors and protective devices – refer to AS3000 Clause 2.5.3.1
IB (
)
≤
IN
(
)
≤
IZ
(
)
Circle Correct Answer
Does the selected cable meet the AS3000 : 2007 IB ≤ IN ≤ IZ requirements?
6077AC MY2011
Yes
 TAFE NSW
No
- 18 -
SECTION C – (Cont’d)
QUESTION 7.
(3 Marks)
Three circuits of four-core V90 circular thermoplastic insulated and sheathed non-armoured
copper conductor cables are buried directly in the ground at a depth of 0.5 m where the
ambient soil temperature is 25ºC. The cables are spaced at a distance of 150 mm from one
another. Each circuit is to carry 100 Amps and protected by 100 Amp circuit breakers.
Use AS/NZS 3008.1.1 to determine a suitable conductor size for the installation.
Multiple Circuits:
De-rating Table No:
Column No:
De-rating factor:
Minimum Current Carrying Capacity of the required
conductor:
Required conductor size:
Table No:
3(
)
Item No:
Table No:
Column No:
Conductor size:
Earth conductor:
Minimum earth conductor size:
Reference:
Coordination between conductors and protective devices – refer to AS3000 Clause 2.5.3.1
IB
(
)
≤
IN
(
)
≤
IZ
(
)
Circle Correct Answer
Does the selected cable meet the AS3000 : 2007 IB ≤ IN ≤ IZ requirements?
6077AC MY2011
Yes
 TAFE NSW
No
- 19 -
SECTION C – (Cont’d)
QUESTION 8.
(3 Marks)
A 230 Volt final sub-circuit consists of a V75 rated multi-core cable and supplies a 25Amp
single phase socket outlet within a factory. A 25A type ‘C’ circuit breaker protects the
circuit. The active and neutral copper conductors have a cross sectional area of 4mm2.
Determine the maximum allowable resistance of the associated 2.5mm2 protective earth
conductor, which is to be measured when the supply is unavailable and the ambient
temperature is 20°C.
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
6077AC MY2011
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- 20 -
SECTION C – (Cont’d)
Use the information in Table 1 as required to answer Questions 9 and 10 of this section.
Table 1
2
Conductor size — mm
6077AC MY2011
Impedance at 50 Hz in Ω/km at 75°C
2.5
9.01
4
5.61
6
3.75
10
2.23
16
1.40
25
0.892
35
0.649
50
0.484
 TAFE NSW
- 21 -
SECTION C – (Cont’d)
QUESTION 9.
(4 Marks)
The diagram below shows a single line diagram representing a supply transformer, consumer
mains to a main switchboard, submain to a distribution board, and a final sub-circuit to an
appliance. An earth fault of zero impedance occurs at the appliance. Calculate the total fault
loop impedance.
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
6077AC MY2011
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- 22 -
SECTION C – (Cont’d)
QUESTION 10.
(6 Marks)
The supply authority has nominated a Prospective Short-Circuit current rating of 30kA at the
point of supply of a 230/400 Volt installation. Given the details provided below, calculate
the Prospective Short-Circuit (P.S.C) current rating at the distribution board. (Note: The
Prospective Short Circuit current is the maximum current that could flow under short circuit
conditions, and is based on a symmetrical three-phase bolted fault).
Description
Consumer Mains
Point of Supply to
MSB
Submain
MSB to Distribution
Board
Length
Cable Type
2
Phases
22 m
50 mm Copper 4 x 1 Core
3
38 m
25 mm2 Copper 4 x 1 Core +
6 mm2 Copper Earth.
3
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
6077AC MY2011
 TAFE NSW
- 23 -
SECTION D – (15 Marks)
INSTRUCTIONS: Answer the following questions in the spaces provided.
Figure 1 shows the time-current characteristic curves for type ‘C’ and type ‘D’ thermalmagnetic circuit breakers of a particular manufacturer. Use this information to answer
question 1 of this section.
(END OF SECTION B)
I/I N
Figure 1
Multiple of rated current
QUESTION 1.
(2 Marks)
A circuit is to be protected by a 50 Amp type ‘C’ circuit breaker. Using the circuit breaker
characteristic curve of Figure 1, determine the approximate minimum and maximum
operating times for a fault current of 200 Amps.
Minimum _____________ seconds
Maximum _____________ seconds
6077AC MY2011
 TAFE NSW
- 24 -
SECTION D – (Cont’d)
INSTRUCTION: The questions in this section require some simple drawing. Ensure that
the drawing is neat and legible. The use of pencil on the drawings is acceptable for questions
3 and 4 in this section only.
QUESTION 2.
(4 Marks)
The following diagram represents the main switchboard of a domestic installation. For
simplification, only a small selection of equipment has been shown.
The unprotected consumer mains entering the main switchboard consist of 16 mm2 active
and neutral conductors. The consumer mains are single insulated within the metallic
enclosure.
On the following diagram, neatly draw in all necessary earthing and equipotential bonding
conductors required to complete an M.E.N system of earthing.
The incoming water service is electrically continuous between the building interior and the
ground.
Based on the given information, determine the minimum size of all earthing conductors,
which is to be shown alongside each conductor (active and neutral conductors need not be
shown).
6077AC MY2011
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- 25 -
SECTION D – (Cont’d)
QUESTION 3.
(6 Marks)
The following diagram represents selected items contained within a domestic electrical
distribution board.
Neatly draw in all active and neutral conductors necessary for the safe and proper operation
of the circuits. Earth conductors need not be shown.
Power circuits P1 and P2 will be individually protected by their own 16A MCB’s.
Light circuits L1 and L2 will be individually protected by their own 16A MCB’s.
Power Circuit P3 is to be protected by a 16A combination RCD/MCB.
All circuits are to be RCD protected.
6077AC MY2011
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- 26 -
SECTION D – (Cont’d)
QUESTION 4.
(3 Marks)
Using the arrangement shown in figure 1, show the connections/disconnections required to
carry out an insulation resistance test on the entire installation.
Correctly marked
drawing = 1 marks
Place an X against
conductors to indicate
disconnection.
Show connections to
meter and bridging
connections if required.
1 mark deducted for
each incorrect answer
or omission.
a)
What range would the insulation resistance tester have to be set to?
_________________________
b)
What position, on or off, would the main switch have to be in?
_________________________
c)
(1 Mark)
(0.5 Mark)
What position, on or off, would each of the final sub-circuit circuit breakers have to
be in?
_________________________
6077AC MY2011
(0.5 Mark)
 TAFE NSW
- 27 Family Name .................................................................................
Given Name ...................................................................................
Student Number ...........................................................................
Centre ............................................................................................
Signature .......................................................................................
ANSWER SHEET – Section A (Multi-choice Questions)
Module - 6077AC
Examination Date: 23 June 2011
Instructions:
•
Enter your name and college on this sheet.
•
Place an X in box of your choice. If you make a mistake- circle your answer
choose again.
•
For your convenience you can remove this page while you answer Section A.
Remember to re-attach it to the paper when you hand it in.
Question
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
a
b
c
X and
d
Totals
Total Correct Section A
Total Marks Section A: ………… /20
END OF EXAMINATION
6077AC MY2011
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- 28 -
Note: The symbols used on this sheet follow AS1046 pt 1. There are alternate recognised
symbols in use. The list does not contain every equation used in the course. Transposition of
equations will be necessary to solve problems
s
t
Q = It
v=
F = ma
W = Fs
W = Pt
η% =
P = VI
P = I 2R
W = mgh
output 100
×
input
1
Rh = Rc (1 + α∆t )
RT = R1 + R2 + R3
VT = V1 + V2 + V3
I T = I1 + I 2 + I 3
V2 = VT
RA R
RB
1
1
1
1
= +
+
CT C1 C2 C3
C=
Rx =
Fm
S
S=
e = Blv
L=
V =L
∆I
∆t
τ=
t=
Fm
l
l
µo µ r A
µo µ r AN 2
l
L
R
Eg =
T = Fr
1
f
f =
V2
R
ρl
R=
A
1
1 1
1
= +
+
RT R1 R2 R3
R1
I 2 = IT
R1 + R2
τ = RC
CT = C1 + C2 + C3
H=
Φ=
R2
R1 + R2
Q
V
Fm = IN
V
R
I=
P=
R1 A1l2
A2l1
R2 =
∆v
t
a=
C=
Aε oε r
d
B=
Φ
A
∆Φ
∆t
∆Φ
L=N
∆I
V =N
F = Bil
ΦZnP
60a
np
120
P=
2πnT
60
V = 0.707Vmax
I = 0.707 I max
Vave = 0.637Vmax
I ave = 0.637 I max
v = Vmax sin φ
i = I max sin φ
I=
X L = 2πfL
XC =
Z = R2 + (X L − X C )
2
6077AC MY2011
V
Z
1
2πfC
 TAFE NSW
- 29 cos φ =
P
S
cos φ =
R
Z
S = P2 + Q2
P = VI cos φ
Q = VI sin φ
VL = 3VP
I L = 3I P
S = 3VL I L
P = 3VL I L cos φ
Q = 3VL I L sin φ
 W − W1 

tan φ = 3  2
 W2 + W1 
Q = mC∆t
V ' = 4.44ΦfN
V1 N1
=
V2 N 2
S = VI
fo =
1
2π LC
N syn =
120 f
p
Vreg % =
s% =
(VNL − VFL ) × 100
VFL
1
I ST = × I DOL
3
2
V 
TST =  ST  × TDOL
 V 
E=
Φv
A
1
(n
I 2 N1
=
I1 N 2
− n ) 100
×
1
nsyn
syn
Vreg % =
(VNL − VFL ) × 100
VNL
1
TST = × TDOL
3
I motor st =
E=
%TAP
× I DOL
100
I
d2
1
fr =
s% × f
100
T=
ΦZIP
2πa
I ST =
VST
× I DOL
V
2
 %TAP 
I line st = 
 × I DOL
 100 
ηv =
Φv
P
VL = 0.45Vac
VL = 0.9Vac
VL = 1.17V phase
VL = 1.35Vline
PRV = 2Vac
PRV = 2 2Vac
PRV = 2.45Vac
Vripple = 2Vac
Vripple = 0.707V phase
Vripple = 0.1895Vline
6077AC MY2011
 TAFE NSW