Unit Name

ELECTRICAL SAFETY - EARTHING/GROUNDING

Unit Code

MEE508

Unit Duration

12 weeks

Award

Graduate Diploma of Engineering (Electrical Systems) Duration: 1 year

Master of Engineering (Electrical Systems) Duration: 2 years

Year Level

One

Unit Creator/Reviewer

Dr Tony Auditore

Core/Elective

Core

Pre/Co-requisites

Nil

Credit Points

3

Grad Dip total course credit points = 24 (3 credits x 8 (units))

Masters total course credit points = 48

(3 credits x 12 (units) + 12 credits (Thesis))

Mode of Delivery

On-Campus or Online

Unit Workload

10 hours per week: Lecture - 1 hour

Tutorial Lecture - 1 hours

Practical / Lab - 1 hour (where applicable)

Personal Study recommended - 7 hours (guided and unguided)

Unit Description and General Aims

The unit introduces engineers to the importance of earthing/grounding, the components of an earthing/grounding system, and the applied methodology to ensure a safe electrical working environment. The science and the art of earthing/grounding is discussed in detail and then applied in case studies. The aims are to introduce the principles, and provide an understanding of earthing/grounding systems in terms of the Australian Competency Standards for Electrical Safety and Earthing/Grounding.

Furthermore, this unit introduces a theoretic point of view on earthing/grounding concepts; thereafter applies these principles in case studies. The role of earthing/grounding engineer is highlighted as a person who is professionally liable for the safety of organisational workers and the general public at large.

Learning Outcomes

On successful completion of this Unit, students are expected to be able to:

  1. Demonstrate theoretical knowledge of subject matter and provide in-depth understanding of Earthing/Grounding principles and theory.

    Bloom’s Level 5

  2. Become aware of the safety issues regarding the potential hazard touch and step voltages within an electrical environment.

    Bloom’s Level 5

  3. Demonstrate ability in identifying the crucial components and their functions within an earthing/grounding system.

    Bloom’s Level 5

  4. Have knowledge of the main international standards and local guidelines for earthing/grounding substation and overhead line design.

    Bloom’s Level 5

  5. Demonstrate ability in applying these standards and guidelines in the design of an earthing/grounding project.

Bloom’s Level 5

Bloom’s Taxonomy

The cognitive domain levels of Bloom’s Taxonomy:

Bloom’s

Level

Bloom’s

Category

Description

1

Knowledge

Recall, define and list facts, concepts, methods, terminologies, theories and structures.

2

Comprehension

Demonstrate understanding by comparing, organizing, describing, translating, interpreting, paraphrasing, explaining and distinguishing.

3

Application

Use knowledge to solve problems, identify connections and show relationships, in context.

4

Analysis

Examine information, breakdown a problem, determine relationships and causes, make inferences, classify and infer from evidence.

5

Synthesis

Produce a pattern from relationships, propose operations, formulate a design,

compose a hypothesis, reassemble information, construct, plan, invent, predict and create.

6

Evaluation

Make judgements based on evidence and external criteria, determine best practice, optimise, validate ideas, judge and critique, assess, valuate and

make recommendations.

Engineers Australia

The Australian Engineering Stage 1 Competency Standards for the Professional Engineer, approved as of 2013. This table is referenced in the mapping of graduate attributes to learning outcomes and via the learning outcomes to student assessment.

Stage 1 Competencies and Elements of Competency

1.

Knowledge and Skill Base

1.1

Comprehensive, theory based understanding of the underpinning natural and physical sciences and the engineering fundamentals applicable to the engineering discipline.

1.2

Conceptual understanding of the mathematics, numerical analysis, statistics, and computer and information sciences which underpin the engineering discipline.

1.3

In-depth understanding of specialist bodies of knowledge within the engineering discipline.

1.4

Discernment of knowledge development and research directions within the engineering discipline.

1.5

Knowledge of engineering design practice and contextual factors impacting the engineering discipline.

1.6

Understanding of the scope, principles, norms, accountabilities and bounds of sustainable engineering practice in the specific discipline.

2.

Engineering Application Ability

2.1

Application of established engineering methods to complex engineering problem solving.

2.2

Fluent application of engineering techniques, tools and resources.

2.3

Application of systematic engineering synthesis and design processes.

2.4

Application of systematic approaches to the conduct and management of engineering projects.

3.

Professional and Personal Attributes

3.1

Ethical conduct and professional accountability.

3.2

Effective oral and written communication in professional and lay domains.

3.3

Creative, innovative and pro-active demeanour.

3.4

Professional use and management of information.

3.5

Orderly management of self, and professional conduct.

3.6

Effective team membership and team leadership.

Graduate Attributes

Successfully completing this Unit will contribute to the recognition of attainment of the following graduate attributes aligned to the AQF Level 9 criteria, Engineers Australia Stage 1 Competency Standards for the Professional Engineer and the Washington Accord and the Program Level Outcomes (PLO):

Graduate Attributes / Program Level Outcomes (Knowledge, Skills, Abilities, Professional and Personal Development)

EA Stage 1 Competencies

Learning Outcomes

A. Effective Communication (PLO 1)

A1. Cognitive and technical skills to investigate, analyse and organise information and ideas and to communicate those ideas clearly and fluently, in both written and spoken forms appropriate to the audience.

2.2, 3.2

1, 3, 5

A2. Ability to professionally manage oneself, teams, information and projects and engage effectively and appropriately across a diverse range of international cultures in leadership, team and individual roles.

2.4, 3.2, 3.4,

3.5, 3.6

4, 5

B. Critical Judgement (PLO 2)

B1. Ability to critically analyse and evaluate complex information and theoretical concepts.

1.1, 1.2, 1.3,

2.1

3

B2. Ability to creatively, proactively and innovatively apply theoretical concepts, knowledge and approaches with a high level of accountability, in an engineering context.

1.5, 2.1, 3.3,

3.4

5

C. Design and Problem Solving Skills (PLO 3)

C1. Cognitive skills to synthesise, evaluate and use information from a broad range of sources to effectively identify, formulate and solve engineering problems.

1.5, 2.1, 2.3

1, 4, 5

C2. Technical and communication skills to design complex systems and solutions in line with developments in engineering professional practice.

2.2, 2.3

1, 2, 5

C3. Comprehension of the role of technology in society and identified issues in applying engineering technology ethics and impacts; economic; social; environmental and sustainability.

1.5, 1.6, 3.1

4, 5

D. Science and Engineering Fundamentals (PLO 4)

D1. Breadth and depth of mathematics, science, computer technology and specialist engineering knowledge and understanding of future developments.

1.1, 1.2, 1.3,

1.4

3, 5

D2. Knowledge of ethical standards in relation to professional engineering practice and research.

1.6, 3.1, 3.5

4, 5

D3. Knowledge of international perspectives in engineering and ability to apply various national and International Standards.

1.5, 1.6, 2.4,

3.4

4, 5

E. Information and Research Skills (PLO 5)

E1. Application of advanced research and planning skills to engineering projects.

1.4, 2.4, 3.6

2, 4

E2. Knowledge of research principles and methods in an engineering context.

1.4, 1.6

1, 3, 5

Unit Content and Learning Outcomes to Program Level Outcomes (PLO) via Bloom’s Taxonomy Level

This table details the mapping of the unit content and unit learning outcomes to the PLOs and graduate attributes at the corresponding Bloom’s Taxonomy level, specified by the number in the table.

 

Integrated Specification /

Program Learning Outcomes

PLO 1

PLO 2

PLO 3

PLO 4

PLO 5

Unit Learning Outcomes

LO1

5

-

5

-

5

LO2

-

-

5

-

5

LO3

5

5

-

5

5

LO4

5

-

5

5

5

LO5

5

5

5

5

5

Unit Study

Assessments

5

5

5

5

5

Lectures/Tutorials

5

5

5

5

5

 

Max Bloom’s level

5

5

5

5

5

Total PLO coverage

6

4

6

5

7

Student assessment

Assessment Type

(e.g. Assignment - 2000 word essay (specify topic) Examination (specify length and format))

When assessed (eg Week 5)

Weighting (% of total unit marks)

Learning Outcomes Assessed

Assessment 1

Type: Multi-choice test / Group work / Short answer questions / Role Play / Self-Assessment / Presentation

Topic examples: Earthing/grounding; function of grounding devices; earth/ground resistance; permitted potential difference, standards; potential)

Week 5

20%

1, 2, 3

Assessment 2

Type: Report / Research / Paper / Case Study / Site Visit

/ Problem analysis / Project / Professional recommendation

Example: Report (Midterm Project)

[This will include a progress report; literature review, hypothesis, and methodology / conclusions]

Word length: 1000

Topic examples: Earth/Ground fault current of a substation. Earthing/Grounding systems for substations. Earthing/Grounding of transmission and distribution lines. Impulse characteristics of earthing/grounding devices. DC Earth/Ground Electrodes. Materials for Grounding. Measurement of Earth/Grounding

Week 8

25%

2, 3, 4

Assessment 3

Type: Report (Final Project)

[If a continuation of the midterm, this should complete the report by adding sections on: methodology, implementation / evaluation, verification / validation, conclusion / challenges and recommendations / future work. If this is a new report, all headings from the midterm and the final reports must be included.]

Word length: 2000

Topic examples: Continuation of midterm.

Final Week

35%

1, 2, 3, 4, 5

Practical Participation

Example: May be in the form of quizzes, class tests, practical assessments, remote labs, simulation software or case studies

Continuous

15%

5

Attendance / Tutorial Participation

Example: Presentation, discussion, group work, exercises, self-assessment/reflection, case study analysis, application.

Continuous

5%

1-5

Prescribed and recommended readings

Required textbook(s)

1. He J; Zeng R and Bo Z, Methodology and Technology for Power System Grounding, 1st Edition, John Wiley & Sons, 2013 (ISBN 9781118254950)

Required standard and guidelines

  1. Energy Networks Association (ENA), EG-0 Power System Earthing Guide Part 1: Management Principles Version 1 – May 2010.

  2. Energy Networks Association (ENA), EG1 – 2006 Substation Earthing Guide.

  3. Required software (available free on internet This email address is being protected from spambots. You need JavaScript enabled to view it.). Requires registration to obtain a usage licence.

  4. ARGON – Safety Assessment Process software

Reference Materials

  • Joffe E B & Lock K-S, Grounds for Grounding, 1st Edition, 2010, ISBN 978-0-471-66008-8, IEEE & Wiley.

  • IDC / EIT notes and Reference texts as advised.

  • Other material advised during the lectures

Unit Content

One topic is delivered per contact week, with the exception of part-time 24-week units, where one topic is delivered every two weeks.

Topics 1 to 8

Introduction to Earthing/Grounding

  1. Introduce the fundamental concepts of earthing/grounding – conduction mechanism of soil, function of grounding devices, definition and characteristics of earth/ground resistance; grounding resistance of grounding devices, body safety and permitted potential difference, and local and international standards related to power system grounding.

  2. Current field in the earth – electrical properties of soil, basic properties of a constant current field in the earth, current field generated by a point of source in uniform soil; potential produced by a point of source on the ground surface in non-uniform soil; and current and potential distributions produced by a DC ground electrode.

  3. Measurement and modelling of soil resistivity – introduction to soil measurement; measurement methods of soil resistivity; simple analysis method for soil resistivity test data; numerical analysis for a multi-layered soil model; and multi-layered soil model by solving Fredholm’s equation.

  4. Earth/Ground fault current of a substation – power station and substation earth/ground faults; maximum fault current through a grounding grid to the earth; simplified calculation of a fault current division factor; typical values of the fault current division factor; influence of seasonal freezing on the division factor.

  5. Earthing/Grounding systems for substations – purpose of grounding; safety of earthing/grounding systems for substations and plant; methods of decreasing the grounding resistance of a substation; equipotential optimal arrangement of an earthing/grounding grid; numerical design of a grounding system.

  6. Earthing/Grounding of transmission and distribution lines – requirement for a tower/pole grounding device; structures of tower/pole grounding devices; properties of concrete encased earthing/grounding; step and touch potentials near a tower/pole; short-circuit fault on transmission/distribution line.

  7. Impulse characteristics of earthing/grounding devices – fundamentals of soil impulse devices; numerical analysis of impulse characteristics of earthing/grounding devices; impulse characteristics of tower earthing/grounding; impulse effective length of earthing/grounding devices; impulse characteristics of a earthing/grounding grid; and lightning electromagnetic field generation by a earthing/grounding electrode.

  8. DC Earth/Ground Electrode – technical requirements for a DC earth/ground electrode; structure types of earth/ground electrodes; main design aspects of a DC earth/ground

    electrode; numerical analysis methods for earth/ground electrode; heat generation analysis of a DC earth ground electrode; and influence of DC earthing/grounding on AC systems.

  9. Materials for Grounding – choice of material and size of conductor; soil erosion of grounding conductor; corrosion of concreter encased electrodes; low-resistivity material; performance of LRM; and construction method of LRM.

  10. Measurement of Earth/Grounding – methods for earthing/grounding resistance measurement; instruments for measuring earthing/grounding resistance; factors influencing the results from the fall of potential method; and the influence of overhead conductors on substation measurement.

Topic 9

Bonding Principles

  1. Objectives of bonding.

  2. Bond impedance requirements.

  3. Types of bonds – direct bonds, indirect bonds, and bonding impedances and effectiveness.

  4. Material surface treatment.

  5. Consideration of dissimilar metals and corrosion control – electrochemical basis of bond galvanic corrosion, electrochemical series, galvanic series, galvanic couples, corrosion protection

Topics 10 and 11

Application of earthing design standards and guidelines

  1. ENA EG1 Substation Earthing Guideline – Coordinated design technique; information gathering and hazard appraisal; allowable voltage criteria; soil resistivity testing, interpretation and modelling; current distribution; power frequency voltage design; D.C. power system design; transient voltage design; installation techniques; testing methods; and maintenance refurbishment.

  2. ENA EG-0 – regulatory framework; standards and codes of practice; earthing management issues; 7 step design process; fault/contact coincidence probability calculation; fibrillation risk analysis; manual probabilistic safety assessment process; As Low As Reasonably Acceptable (ALARA) design process.

  3. Case studies on earthing/grounding designs.

Topic 12

Project and Revision

In the final week students will have an opportunity to review the contents covered so far. Opportunity will be provided for a review of student work, to clarify any outstanding issues, and to work on finalising the major assessment report.

The Engineering Institute of Technology (EIT) is dedicated to ensuring our students receive a world-class education and gain skills they can immediately implement in the workplace upon graduation. Our staff members uphold our ethos of honesty and integrity, and we stand by our word because it is our bond. Our students are also expected to carry this attitude throughout their time at our institute, and into their careers.