Last Updated S012019

MEE508

Unit Name ELECTRICAL SAFETY - EARTHING/ GROUNDING
Unit Code MEE 508
Unit Duration 1 Term (online) or 1 Semester (on-campus)
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))

Master total course credit points = 48

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

Mode of Delivery Online or on-campus. 
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 6
2. Become aware of the safety issues regarding the potential hazard touch and step
voltages within an electrical environment.
Bloom’s Level 6
3. Demonstrate ability in identifying the crucial components and their functions within an
earthing/grounding system.
Bloom’s Level 6
4. Have knowledge of the main international standards and local guidelines for
earthing/grounding substation and overhead line design.
Bloom’s Level 6
5. Demonstrate ability in applying these standards and guidelines in
the design of an earthing/grounding project.
Bloom's Level 6

Student assessment

Assessment Type

(e.g. Assessment -2000 word essay (specify topic)

Examination ( specify length and format))

When assessed

(e.g 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
 
 
Continous 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.

 

Topic 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 multilayered 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

 

Topic 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.