Lightning Protection, Safety and Insulation Coordination for Power Systems Course

Introduction:

Equipment Earthing should be differentiated from system earthing since the functions of the two are often confused. A "system earth" is a connection to ground from one of the current-carrying conductors of a distribution or wiring system. The return conductor for a line-to-neutral load on either single or multi-phase systems is an example of such a current-carrying conductor. This system ground may be made at such locations as transformer or generator neutral points by either a solid connection or through a current limiting device.

Course Objectives:

• The basic principles & importance of earthing of electrical systems.
• The function of the power system earthing and the various options available.
• Role of protective grounding in ensuring safety; sizing of grounding conductors.
• Importance of equipotential bonding in ensuring safety.
• Design of ground electrodes, measurement of soil resistivity, and ground electrode resistance.
• Fundamental principles in the design of grounding systems in substations.
• Solving static electricity-related hazards by grounding and bonding.
• Role of grounding in surge protection of power distribution equipment and sensitive systems.
• How to test and maintain earth electrode & Earthing grid.

Who Should Attend?

This 5 days course is designed to maximize delegate benefit from the outset. The goals of each participant are discussed to ensure their needs are fulfilled as far as possible. Questions are encouraged throughout particularly at the daily wrap-up sessions. This provides opportunities for participants to discuss specific issues and if possible find appropriate solutions. Case studies are employed to highlight particular points and appropriate video material used to illustrate particular conditions. Some videotapes will support classes.

Course Outlines:

•  What is System Earthing?
• Why Use System Earthing.
• Basics of grounding/earthing & Bonding.
• Objectives of equipotential bonding.
• Different types of functional & Protective earthing.
• Electricity shock & hazards & Equipment earthing
• Static charges and the need for bonding.

• Different Types of System or Neutral Earthing.
• Systems with an isolated neutral-point.
• Reactance earthed systems.
• Resistance earthed systems.
• Earthed system:
• Effectively earthed system.
• Not effectively earthed system.
• Zigzag earthing transformer.
• Sizing of Earthing resistors & Zigzag transformers.
• To Choose System’s Earthing Point.
• The practice of Earthing.
• Comparison of Different system Earthing Principles
• Earthing & Earth fault protection.
• Different earthing of distribution system arrangements (TT, TN-C, TN-S & IT) as per BS 7671 & IEC 60364.

• Static electricity and protection.
• Lightning & surge arresters.
• Transient overvoltage’s.
• PQ problems & triple harmonics (Zero phase sequence).
• Ground electrode system.

• Substation earthing grid.
• Touch & Step voltages.
• Grounding regulations from various national codes.
• BS 7430 & IEEE 80 Standards.
• Maintenance & testing (3 pin method, 61.8% and slope method).
• Finite Element Method (FEM).

• Methods of designing Grounding systems.
• Ground faults.
• Design cases (Grounding module) & Reporting.