An Introduction to Safety Grounding

Cover
Half Title
Title Page
Copyright Page
Table of Contents
Preface
Chapter 1 Effect of Current on the Human Body
	1.1 Introduction
	1.2 Effect of Electric Shock on Human Beings
	1.3 Effect of Current Duration
	1.4 The Electric Resistance of the Human Body
Chapter 2 Resistance to Ground
	2.1 Resistance to Ground of a Hemisphere
	2.2 Measurement of Electrode Resistance to Ground
	2.3 Soil Resistivity
	2.4 Measurement of Soil Resistivity
		2.4.1 Simple Box Method
		2.4.2 Wenner Method
		2.4.3 Electromagnetic Induction Method
	2.5 Computer Programs
Chapter 3 Earthing Electrodes
	3.1 Single Driven Rod
	3.2 Grounding Using Multiple Rods
	3.3 Grounding Using Horizontally Buried Wires
	3.4 Grounding Using Buried Plates
	3.5 Water Pipes or Steel Reinforcement as Grounding Electrodes
	3.6 The Resistance Area
Chapter 4 Step, Touch, and Transfer Voltages
	4.1 Step Voltage
	4.2 Touch Voltage
	4.3 Transfer Touch Voltage
	4.4 Grounding of Power Towers
		4.4.1 Effect of Overhead Ground Wire on Tower Footing Resistance
Chapter 5 Grounding Systems
	5.1 Magnitude of Resistance to Ground
	5.2 Elements of the Grounding System
		5.2.1 The Area of Land
			5.2.1.1 Use of Chemical Salts
			5.2.1.2 Increasing the Soil’s Ability to Retain Water
		5.2.2 Ground Electrodes
			5.2.2.1 Driven Rods
			5.2.2.2 Concrete-Encased Electrodes
			5.2.2.3 Water and Gas Pipes
			5.2.2.4 Structural and Reinforcing Steel
			5.2.2.5 Equipotential Bonding
		5.2.3 Connections in Grounding Systems
		5.2.4 Grounding Conductors
			5.2.4.1 Size of Grounding Conductors
			5.2.4.2 Protective Sleeve
		5.2.5 Ground Connection Provisions
		5.2.6 Equipment Grounding Conductors
			5.2.6.1 Conductor Size according to the Adiabatic Equation
			5.2.6.2 Conductor Size According to USA Specifications (NFPA-70)
			5.2.6.3 Metal Cable Trays as Grounding Conductors
			5.2.6.4 Flexible Metal Conduits
			5.2.6.5 Cable Sheath and Armor
			5.2.6.6 Jumpers
	5.3 Metallic Corrosion
	5.4 General Rules for the Grounding of Branch Substations
	5.5 Protective Grounding of Consumer Installations: Types of Grounding Systems
		5.5.1 The TN-C System
		5.5.2 The TT System
		5.5.3 The TN-S System
		5.5.4 Protective Multiple Earthing
		5.5.5 The IT System
	5.6 Protection by Isolation
	5.7 Grounding of Computers and Data Processing Equipment
Chapter 6 Substation Grounding Systems
	6.1 Introduction
	6.2 Design Steps
		6.2.1 Ground Mat Resistance
		6.2.2 Calculation of Maximum GPR
		6.2.3 Determination of Maximum Touch and Step Voltages
		6.2.4 Safety Requirements
	6.3 Design of Ground Mat using Computer Program
Chapter 7 Static Electrification
	7.1 Introduction
	7.2 Conditions Necessary for Ignition
		7.2.1 Explosion Limits
		7.2.2 Oxygen
		7.2.3 Ignition Sources
		7.2.4 Minimum Ignition Energy
	7.3 Generation of Electrostatic Charges
		7.3.1 Contact Electrification between Solid Surfaces
		7.3.2 Static Electrification in Liquids and Gases
	7.4 Ways for Reducing the Formation of Surface Charges
	7.5 Electrostatic Induction
	7.6 Types of Electric Discharges
		7.6.1 The Spark or Arc Discharge
		7.6.2 Brush Discharges and Propagating Brush Discharges
		7.6.3 Corona Discharges
	7.7 Methods of Controlling Electrostatic Charges
		7.7.1 Grounding and Bonding
		7.7.2 Floors and Clothing for Static Control
			7.7.2.1 Static Conductive Floors
			7.7.2.2 Static Dissipative Floors
		7.7.3 Control of Humidity
		7.7.4 Ionization
Chapter 8 Protection against Lightning
	8.1 Nature of Lightning
	8.2 Why Protect against Lightning
	8.3 Lightning Protection System
		8.3.1 The Air Terminals
		8.3.2 Mesh Air Termination Networks
		8.3.3 Down Conductors
		8.3.4 Types of Conductors
		8.3.5 Grounding
	8.4 Inductance, Side Flashing, and Separation Distance
	8.5 Zones of Protection
	8.6 Tanks and Stacks
	8.7 Protection of Transmission Lines by Aerial Ground Wires
		8.7.1 Secondary Field of Ground Conductor
		8.7.2 Height of Ground Conductor
	8.8 Protection against Surges
Appendix A: Wire Sizes
Bibliography
Index