This course focuses on the building blocks of grounding of electrical systems. Unnecessary theory is reduced to allow you to focus on best practices over the duration of the course.
Few topics generate as much controversy and argument as that of grounding or earthing and the associated matters of lightning and surge protection of electrical and electronic systems. Any engineer or technician dealing with power supply networks needs to understand the basic principles of grounding system design and its role in ensuring safety of equipment and personnel. A correct understanding of the basic principles involved will help to avoid mistakes in grounding system design; mistakes that could lead to expensive failures and long downtime.
In this course, we aim to demystify the concepts of grounding as applicable to utility networks and industrial plant distribution systems as well as their associated control equipment. In fact, a lot of myths have been built around this subject, although it is quite a simple one when approached from basic principles. Our endeavour will therefore be to explain the fundamentals of grounding, which we hope will enable the participants to gain a correct perspective of the subject and give them the knowledge needed to solve real life grounding problems.
The course is value packed with multiple videos and example exercises.
WHO SHOULD COMPLETE THIS COURSE?
- Building service designers
- Consulting engineers
- Data systems planners and managers
- Electrical and instrumentation technicians
- Electrical engineers
- Instrumentation and control engineers
- Maintenance engineers
- Power system protection and control engineers
- Project engineers
YOU WILL LEARN
- The basic principles of grounding of electrical systems
- The function of power system grounding and the various options available
- Fundamental principles in the design of grounding systems in substations
- How to solve static electricity-related hazards by grounding and bonding
COURSE OUTLINE
OVERVIEW
- Objectives of grounding and bonding
- Fault in an underground system
- Effect of neutral system grounding
- Ground fault current flow
- Ground electrodes
- Grounding for charge/surge control
- Dissipation of static charges
- Lightning strikes
- Sources of voltage surge
- Typical ground loops
STATIC ELECTRICITY AND PROTECTION
- What is static electricity and how is it generated?
- Examples of static charge build up and its dangers
- Energy of spark due to static electricity
- Ways of controlling static build up
- Risk assessment and preventive measures
GROUNDING FOR LIGHTNING PROTECTION OF BUILDINGS AND STRUCTURES
- The physics of lightning
- Lightning incidence in different land masses
- Lightning strike probability
- Lightning protection
- Planning for protection and decision factors
- Improved approach to lightning protection and non-conventional systems
- Effect of lightning strikes on electrical installations
POWER SUPPLY SYSTEM GROUNDING
- Types of system grounding
- Ungrounded systems
- Solidly grounded systems
- Impedance grounding using neutral reactor
- Resonant grounding using neutral reactor
- Impedance grounding through neutral resistance
- Classification of supply systems based on grounding
- Point of grounding
- Other challenges
PROTECTIVE GROUNDING
- Electric shock, its cause and effects
- Direct and indirect contact
- Touch and step potential
- Role of protective grounding in minimising the shock hazards
- Equipotential bonding
- Protective grounding conductors and installation
- Ground fault protection
- System classification based on system/protective grounding
SURGES AND SURGE PROTECTION
- Surges, their causes and mitigation
- The ways by which surges couple into electrical circuits
- Bonding of grounding systems
- Basic principle of surge protection and commonly used surge protection devices
- Graded surge protection
- Selecting appropriate surge protective devices and their positioning in a system
GROUND ELECTRODE SYSTEMS
- Soil resistance and factors affecting soil resistivity
- Measurement of soil resistivity
- Resistance of ground electrode and distribution of resistance in surrounding soil layers
- Electrode current capacity
- Ground electrode configurations
- Parallel electrodes
- Ground electrode resistance measurement
- Chemical electrodes
- Concrete encased electrodes and splicing methods
- Corrosion of buried electrodes
- Grounding system maintenance
ELECTRICAL NOISE AND MITIGATION
- Definition of electrical noise
- How are sensitive circuits affected?
- Noise categories
- Noise from power electrical equipment
- Noise coupling into signal circuits
- Noise mitigation measures
- Role of proper grounding in reducing noise
- Noise control by proper grounding of UPS derived supplies
SUBSTATION GROUNDING DESIGN
- Grounding practices
- Basic design approach
- Calculating the ground fault current
- Ground potential rise in HV systems
- Grounding design in LV and MV substations/installations
- Grounding grid design for HV/EHV substations - a step-by-step approach
- Introduction to two-layer soil model
- Transferred potential and ways of avoiding
- Points needing special attention in substation grounding design and for GIS equipment
- Design of substations containing converter equipment feeding to HVDC transmission systems
- Ensuring effective substation grounding - important aspects
