REPORT 191 PROGRAMMES

SUBJECT SYLLABUS

ELECTROTECHNICS N4

SUBJECT CODE: 8080074

IMPLEMENTATION: JANUARY 2021

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CONTENTS PAGE

1. General Aims ............................................................................................................... - 3 -

2. Specific Aims .................................................................................................................. 3
3. Pre-requisite...................................................................................................................................3
4. Duration............................................................................................................................ 3
5. Evaluation .................................................................................................................... - 4 -
6. Learning content ......................................................................................................... - 5 -
7. Mark allocation in the examination as an indication of the weighting of the different
modules........................................................................................................................ - 5 -
Module 1: Principles of Electricity ......................................................................................... - 6 -
Module 2: Direct Current (DC) Machines ................................................................................... 9
Module 3: Alternating- Current (AC) Theory ........................................................................... 11
Module 4: Transformer ............................................................................................................. 13
Module 5: Alternating Current (AC) Machines ........................................................................ 14
Module 6: Generation and Supply of Alternating Current (AC) Power .................................. 15
Module 7: Measuring instruments ........................................................................................... 16
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Syllabus: Electrotechnics N4

1. General Aims

To provide students with knowledge and skills that are used in an electrical industry.
To develop students’ ability to solve electrical problems and adhere to safety standards
and procedures.

2 Specific Aims

 The student should obtain a thorough background of the necessity for

Electrotechnics as it is applied in industry.
 The student should be able to classify individual electrical components into various
stages as found in electrical apparatus on his/her own.
 The teaching of this subject is aimed at:

 Introduction to the application of technological principles such as design

procedures; and
 The relationship between Electrotechnology and other scientific subjects.

3. Pre-requisite
Student must meet at least one of the following requirements.

3.1 Completed National N3 certificate with Electrotechnology N3 or Electrical Trade

Theory N3.
3.2 Passed grade 12 with at least level 4 (50% or D symbol) in Mathematics and Natural
Science or Electrical subjects.
3.3 Completed NCV level 4 in any engineering programme.
3.4 Passed senior certificate for adult learners with at least level 4 (50% or D symbol) in
Mathematics and Physical Science.

4. Duration
Full-time: 7.5 hours per week. This instructional offering may also be offered part-
time.
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5. Evaluation
5.1 Evaluation is conducted continuously by means of two formal tests at College level.
Learner must obtain a minimum ICASS mark of at least 40% in order to qualify to
write the final examination and a mark will be calculated together in a ratio of 40:60
to derive the promotion mark. The learner must obtain at least 40% on the final
examination.

The promotion mark will be calculated as follows:

Promotion Mark = 40% of (ICASS mark) + 60% of (Exam mark)

5.2 The examination in Electrotechnics N4 (Engineering Studies - Report 191) will be

conducted as follows:

Modules 1 to 7 MARKS: 100

DURATION: 3 HOURS

CLOSED BOOK: Formula sheet is attached to the question paper

Scientific calculators allowed
No programmable calculators allowed
No references allowed.
No external examination papers or memoranda allowed

5.3 Weighting:

The following weights are consequently awarded to each category:

Knowledge and Understanding Applying Analysing / Synthesis and

Evaluating
30 – 40 30 – 40 20 – 25
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6. Learning content
THEORETICAL BACKGROUND

It is essential that this subject should be illustrated and evaluated within the context of
practical case studies.

TECHNICAL BACKGROUND

It is essential that this subject should be illustrated and evaluated within the context of
technical skills and simulation of practical environment.

7. Mark allocation in the examination as an indication of the

weighting of the different modules

MODULES WEIGHTING
1. Principles of Electricity 30
2. DC-machines 20

3. AC-Theory 20
4. Transformers 10

5. AC-machines 10
6. Generation and supply of AC-Power 5
7. Measuring Instruments 5
TOTAL 100
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Module 1: Principles of Electricity

General aim

On completion of this module, the student should be able to explain the theoretical and
practical application of the following concepts: electrical circuits, electromagnetism,
magnetic circuits, Inductance in DC-circuits, Capacitors in DC-circuits, Kirchhoff’s Laws
and Norton’s Theorems.

LEARNING OUTCOMES
LEARNING CONTENT The student must be able to:

1.1 Electric circuits 1.1.1 Explain the difference between EMF (Electro-Motive
Force) and terminal voltage.
1.1.2 Draw labelled circuit diagrams of resistive series-,
parallel- and series/parallel networks and determine
by calculation:
 Electro-Motive Force;
 Terminal voltage;
 Voltage drops;
 Current flowing in each branch;
 Values of resistors;
 Power and energy.
1.2 Resistivity 1.2.1 List the factors that will affect the resistance of a
conductive material and explain the effect of each
factor.
1.2.2 Calculate the following with regards to conductive
material:
 Resistance;
 Resistivity;
 Length;
 Cross-sectional area
 Current; and
 Voltage drop.
1.2.3 Explain reasons for connecting conductors in parallel.

1.2.4 Calculate the following with regards to parallel

connected conductor materials;
 Resistance;
 Resistivity;
 Length;
 Cross-sectional area
 Current; and
 Voltage drop.
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1.3 Temperature 1.3.1 Define the temperature coefficient of resistance and
coefficient of explain the effect of positive and negative temperature
resistance coefficient of resistance.
1.3.2 Calculate the following items when temperature of
resistance is at 00C and when temperature coefficient
of resistance is at an initial temperature:
 Temperature coefficient of resistance
 Initial or final temperature; and
 Initial or final resistance.
1.4 Kirchhoff’s Laws 1.4.1 State Kirchhoff’s first- and second Laws. (Voltage- and
Current Laws). The use of relevant network diagrams
to enhance your description is imperative.
1.4.2 Draw relevant labelled circuit diagrams and determine
by calculation regarding Kirchhoff’s Laws:
 EMF;
 Terminal voltage;
 Voltage drops;
 Current;
 Values of resistors
 Power and energy.
1.5 Norton’s Theorem 1.5.1 State Norton’s Theorem and use relevant network
diagrams to enhance your description.
1.5.2 Draw relevant labelled circuit diagrams and determine
by calculation regarding Norton’s Theorem:
 Load resistance;
 Load current;
 Load voltage;
 Short circuit current;
 Open circuit resistance;
The use of relevant network diagrams is imperative,
and sources are limited to TWO.
1.6. Magnetism and 1.6.1 List the characteristics of magnetic field lines and the
Electromagnetic applications of electromagnetic induction.
Induction 1.6.2 State the following Laws and rules and use relevant
sketches where applicable to enhance your
description:
 Right-hand rule to determine the direction of
magnetic field lines around a current carrying
conductor;
 Right-hand grip rule;
 Fleming’s left-hand rule;
 Fleming’s right-hand rule;
 Lenz’s Law; and
 Faraday’s Law
1.6.3 Calculate the following regarding a magnetic circuit:
 MMF;
 Number of turns;
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 Current;
 Reluctance;
 Magnetic field strength;
 Magnetic flux; and
 Flux density.
1.6.4 Calculate the following regarding a current carrying
conductor:
 Force exerted;
 Length of conductor;
 Flux density; and
 Current carrying capacity.
1.6.5 Calculate the following regarding electromagnetic
induction:
 EMF;
 Magnetic flux;
 Inductance;
 Current;
 Time; and
 Number of turns.
1.7 Capacitors 1.7.1 Define the following concepts:
 Capacitance
 Farad
 Coulomb;
1.7.2 Explain with the aid of suitable graphic representations
the charge- and discharge characteristics
1.7.3 Draw labelled circuit diagrams of capacitor series-,
parallel- and series/parallel networks and determine
by calculation:
 Total capacitance;
 Accumulated charge; and
 Voltage drops.
Module 1 – Principles of Electricity
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Module 2: Direct-Current Machines

General aim

On completion of this module, the student should be able to explain and apply the
construction, operation of DC-Machines including performing all relevant calculations.

LEARNING OUTCOMES
LEARNING CONTENT The student must be able to:

2.1 Construction of DC- 2.1.1 Draw DC-machine that will illustrate the construction
machines and label the main parts
2.1.2 List and explain the function of each component of a
DC-machine.
2.1.3 Explain and show by means of labelled sketches the
difference between lap- and wave-wound armature
winding constructions.
2.1.4 Explain the different applications of lap-wound and
wave-wound machines.
2.2 Operation of DC- 2.2.1 Explain the principle of operation of a DC-motor and
machines DC-generator.
2.2.2 Explain the function of the brushes in DC-machines
and list different types of brushes in use and why such
brushes are used.
2.2.3 Define and list the effects of armature reaction in DC-
machines.
2.2.4 Describe the methods used in minimising the effects
of armature reaction in DC-machines.
2.2.5 Describe the effects of commutation in DC-machines.
2.2.6 Describe the methods of improving commutation in
DC-machines.
2.3 Field winding of 2.3.1 Draw and label circuit diagrams for the following self-
DC-machines excited DC-machines:
 Series wound;
 Shunt wound;
 Long shunt compound wound; and
 Short shunt compound wound.
2.3.2 Calculate the following quantities with regards to
series-wound DC-motors and generators, shunt-
wound DC-motor and generator, long shunt
compound wound DC-motor and generator and short
shunt compound wound DC-motor and generator:
 EMF;
 Speed;
 Magnetic flux;
 Number of poles;
 Number of parallel paths;
 Armature conductors;
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 Terminal voltage;
 Supply current;
 Field current;
 Armature current;
 Field resistance; and
 Armature resistance.
2.4 Characteristics and 2.4.1 List the characteristics of DC-motors and DC-
applications of DC- generators.
machines 2.4.2 Describe applications of series, shunt, short shunt
compound and long shunt compound DC-motors and
generators.
2.5. DC-motor starters 2.5.1 Explain the purpose of a DC-motor starter.
2.5.2 Draw and label circuit diagrams to illustrate how a
face-plate starter is connected in a DC-series and
shunt DC-motor.
2.5.3 Calculate the following quantities with regards to DC-
motor starters:
Starting current;
Starter resistance; and
Terminal voltage.
2.6 No-load / Open 2.6.1 Draw a no-load characteristic curve of a DC-motor,
Circuit characteristics using the field current and EMF generated.
of DC-motor 2.6.2 Calculate the critical resistance and the value of
voltage to which the machine will excite under no- load
from the no-load characteristic curve of a DC-motor
Module 2 – Direct Current Machines
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Module 3: Alternating-current Theory

General aim
On completion of this module, the student should be able to explain the generation of EMF,
series and parallel RLC circuits and power in single-phase AC- circuits.

LEARNING OUTCOMES
LEARNING CONTENT The student must be able to:

3.1 Generation of EMF 3.1.1 Illustrate by means of a graphic representation the

generation of an alternating quantity of voltage and
current with respect to time.
3.1.2 Calculate the following quantities with regard to an
alternating quantity:
 Maximum value;
 RMS value (Root Mean Square);
 Average value;
 Instantaneous value;
 Frequency;
 Time;
 Period;
 Angular velocity;
 Form-factor; and
 Crest-factor.
3.1.3 Define with regard to an alternating quantity:
 Period;
 Cycle;
 Instantaneous value;
 Form-factor; and
 Crest-factor.
3.2 RLC-circuits 3.2.1 Draw phasor diagrams and wave forms of voltage
versus current relationship in single-phase circuit when
an alternation quantity is applied to a:
 Resistor;
 Inductor; and
 Capacitor.
3.2.2 Draw a circuit diagram for series and parallel RLC-
circuits and calculate the following:
Resistance;
Inductance;
Inductive reactance;
Capacitance;
Capacitive reactance;
Impedance;
Voltage drops;
Supply voltage;
Current;
Phase angle;
Power; and
Power factor.
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3.3 Power in AC- 3.3.1 Describe and calculate:
circuits True power;
Apparent power;
Reactive power; and
Power factor.
3.3.2 Describe the effects of low power factor.
3.3.3 Describe methods of improving low power factor.
Module 3 – Alternating current theory
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Module 4: Transformers
General aim

On completion of this module, the student should be able to explain and apply principle of
operation of single-phase transformer, construction of single-phase transformers and
perform relevant calculations for the following quantities: currents, voltages, turns ratio,
flux, power and power factor.

LEARNING OUTCOMES
LEARNING CONTENT The student must be able to:

4.1 Basic construction 4.1.1 Draw and label the basic construction of a single-
of a single-phase phase transformer.
transformer
4.2. Basic operation of 4.2.1 Explain the basic operation of a single-phase
a single-phase transformer
transformer 4.2.2 Describe the characteristics of an ideal transformer.
4.2.3 Use the transformer equation to calculate the following
quantities with regard to single-phase transformers;
 Turns ratio;
 Voltages;
 Number of turns;
 Flux density; and
 Power.
4.3 Transformer on 4.3.1 Draw and label circuit diagram and vector diagram of
no-load a transformer with no-load.
4.3.2 Calculate the following with regards to a transformer
with no load:
 No load current;
 Core loss current;
 Magnetising current;
 Power; and
 Power factor.
4.4 Transformer 4.4.1 Describe the methods used for the cooling of
cooling transformers.
4.5 Transformer 4.5.1 List types of transformer losses that can occur in a
losses transformer.
Module 4 – Transformers
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Module 5: AC-machines
General aim

On completion of this module, the student should be able to explain and apply the principle
of operation of single-phase and three-phase motors, construction of single phase- and
three phase induction motor.

LEARNING OUTCOMES
LEARNING CONTENT The student must be able to:

5.1 Basic construction 5.1.1 Describe the three main parts of an induction motor.
of induction motor
5.1.2 Describe the two types of rotors of a three-phase
induction motor
5.2 Basic operation of 5.2.1 Explain the basic operation of a three-phase induction
an induction motor motor.
5.2.2 Define slip.
Explain the function of slip.
Calculate the following with regards to an induction
motor:
 Slip;
 Frequency;
 Poles;
 Synchronous speed; and
 Rotor speed.
5.2.3 Describe the applications of an induction motor.
5.3 Motor starters 5.3.1  Draw labelled circuit diagrams for a single-phase
induction motor that makes use of:
 Resistance starting;
 Capacitor starting; and
 Capacitor start capacitor run.
5.3.2 Explain how to reverse the rotation of an induction
motor.
Module 5 – AC-machines
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Module 6: Generation and supply of AC power

General aim

On completion of this module, the student should be able to explain power generation,
transmission and distribution of AC-power to consumers.

LEARNING OUTCOMES
LEARNING CONTENT The student must be able to:

6.1 Generation 6.1.1 Describe different types of power stations.

6.1.2 Explain reasons for power stations to be far away from
load centres.
6.2. Transmission 6.2.1 Explain reasons for transmission of power at high
voltage.
6.3. Distribution 6.3.1 Describe and draw diagrams of types of feeders and
explain the advantages and disadvantages of each
type of feeder.
Module 6 – Generation and supply of AC power
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Module 7: Measuring instruments

General aim

On completion of this module, the student should be able to explain the principle of
extending the range of measuring instruments, calculate series- and shunt resistance
values and resistive values with the aid of the ammeter-voltmeter method.

LEARNING OUTCOMES
LEARNING CONTENT The student must be able to:

7.1 Instrument shunt- 7.1.1 Explain the purpose of shunt and series resistors in
and series additional measuring instruments.
components. 7.1.2 Calculate the resistor values required when voltage
and/or current is measured in order to extend the
range of the volt meter and ammeter:
 Shunt resistors; and
 Series resistors.
7.2 Measurement of 7.2.1 Apply short- and long shunt voltage-ammeter method
resistance to calculate the following;
 Apparent resistance value;
 Exact resistance value; and
 Percentage error value.
7.2.2 Apply the results of Wheatstone Bridge experiment to
calculate the value of the unknown resistor
Module 7 – Measuring Instruments