Practical Guide to Electrical Grounding.
1 Building and Service Entrance Grounding
2 Building Lightning Protection – A critical extension of grounding
3 Building Interior Bonding and Grounding – The bonding and 47 grounding of building steel, electrical panels and other power systems equipment
4 Transients & Other High Frequency Bonding and “Grounding” Requirements 65 The bonding and grounding of electronic systems
5 Selection of Components Used in Grounding
6 Special Grounding Situations – Areas not covered elsewhere
7 Application of Surge Protection Device
This book is designed for the contractor who finds that installing grounding systems, which are in compliance with all relevant codes and standards, is a complex and somewhat mystifying assignment. While in larger facilities, the design of a proper grounding system is certainly complex and should be left to a qualified engineer, the everyday grounding installations and applications covered in this text are well within the scope of the qualified contractor. In most facilities, a thoughtful contractor can follow the guidelines and techniques in this book and be reasonably ensured that he has done a competent and code compliant job. This book is not written for the casual contractor who was in the painting business last week. It is for the electrical contractor who intends to be in business next week, next year, and in the years to come. Design and installation of electrical grounding systems is one of the most important aspects of any electrical distribution system, yet it is all too often misunderstood and subsequently installed improperly. Some detailed knowledge of the facility is needed, and the contractor who intends to do the job correctly must make the investment in time and tools – or hire someone to do these things for him. Guesswork won’t do! The subject is too serious and complex for that kind of approach. We hope you find our recommended approaches helpful and cost-effective.
Article 250 of the National Electrical Code (NEC) contains the general requirements for grounding and bonding of electrical installations in residential, commercial and industrial establishments. Many people often confuse or intermix the terms grounding, earthing and bonding. To use simple terms:
Grounding is connecting to a common point which is connected back to the electrical source. It may or may not be connected to earth. An example where it is not connected to earth is the grounding of the electrical system inside an airplane.
Earthing is a common term used outside the US and is the connection of the equipment and facilities grounds to Mother Earth. This is a must in a lightning protection system since earth is one of the terminals in a lightning stroke.
Bonding is the permanent joining of metallic parts to form an electrically conductive path that will ensure electrical continuity and the capacity to conduct safely any current likely to be imposed. A comprehensive review of grounding and bonding requirements contained in the NEC appears in Chapter 3 of this text.
Download Practical Guide to Electrical Grounding in free pdf format.