1 General
1.1 Scope
1.2 Purpose of protective grounding
1.3 References
2 Definitions
3 Principles
3.1 Introductions
3.2 General
3.2.1 Voltages at the work site
3.2.2 Body current limits
3.2.3 Body resistance, Rb
3.2.4 Clothing and footwear resistance, Rc
3.2.5 Contact resistance, Rg
3.3 Fault currents
3.3.1 Magnitude
3.3.2 Duration
3.3.2.1 Breaker reclosure considerations
3.4 Induction coupling
3.4.1 Capacitive coupling
3.4.2 Magnetic coupling normal conditions
3.4.3 Magnetic coupling during faults
3.5 Lightning
4 Rating of grounding sets
4.1 Ground set components
4.1.1 Cable rating
4.1.2 Cable material
4.1.3 Electrical resistance
4.1.3.1 Resistance variations
4.1.3.2 Cable characteristics
4.1.3.3 One cable
4.1.3.4 Requirements for multiple cables
4.1.3.4.1 Length
4.1.3.4.2 Cross section
4.1.3.4.3 Material
4.1.3.4.4 Connections
4.1.3.4.5 Proximity
4.2 Grounding cable size
4.2.1 Rating of grounding cable
4.2.1.1 Withstand capacity rating
4.2.1.2 Ultimate capacity rating
4.2.1.3 Mechanical consideration
4.2.2 Clamp rating
4.2.2.1 Clamps - aluminum alloy
4.2.2.2 Clamps - copper alloy
4.2.2.3 Resistance changes in use
4.2.2.4 Electrical ratings
4.2.2.5 Mechanical stresses during
faults
4.2.2.6 Clamp form
4.2.2.7 Clamp size selection
4.2.2.8 Jaw configuration
4.2.2.9 Corrosion effects
4.2.2.10 Mounting methods
4.2.3 Clamp connection
4.2.4 Circuit configuration
4.2.5 Resistance of ground
5 Grounding practices
5.1 Introduction
5.2 Theoretical considerations
5.2.1 Multiple grounding cables
5.2.1.1 Path impedance
5.2.1.2 Positioning
5.2.1.3 Maximum grounding sets paralleled
5.2.2 De-rating
5.2.3 Station grounds parallel with protective
grounding cables
5.2.4 Precautions
5.2.4.1 Cables subject to fault current
5.2.4.2 Cable reuse
5.2.5 Work-site Vs. bracket grounding sets
5.2.6 Single-phase Vs. Three-phase grounding
5.2.7 Bonding
5.2.8 Ground electrode
5.3 Distribution line grounding
6 Power line construction
7 Work procedures
7.1 Introduction
7.2 Voltage detection methods
7.2.1 Buzzing
7.2.1.1 Live line tool methods
7.2.1.2 Noisy tester method
7.2.1.3 Voltage detectors
7.2.1.4 Neon detectors
7.2.1.5 Hot horn or noisy tester
7.2.1.6 Multiple range voltage detector
(MRVD)
7.3 Advantages and disadvantages of voltage detectors
7.3.1 Neon indicator
7.3.2 Noisy tester voltage detector
7.3.3 Multiple range voltage detector
7.4 Cleaning conductor and ground connections
7.4.1 Purpose
7.4.2 Equipment and method
7.4.2.1 Wire brushing
7.4.2.2 Self-cleaning clamps (SCCs)
7.4.3 Metal structures
7.4.3.1 Steel pole structures
7.4.3.2 Weathering steel pole structures
7.4.3.3 Painted steel tubular structures
8 Grounding procedures
8.1 Preliminary
8.1.1 Methods of use
8.2 Installation procedure
8.2.1 Structures
8.2.1.1 Lattice structures
8.2.1.2 Painted and galvanized steel
pole structures
8.2.1.3 Composite and concrete structures
8.2.1.4 Wooden structures
8.2.3 Length of grounding conductors
8.2.4 Problems of control
8.3 Removing grounds
8.3.1 Method
8.3.2 Precautions
9 Vehicles and equipment - methods of protection -
workers and public
9.1 Methods
9.2 Vehicle grounding
9.2.1 Aerial devices
9.2.2 Other work vehicles
9.2.3 Vehicles connected to station service
10 Maintenance
10.2 Inspection and maintenance of protective grounds
10.3 Testing
10.3.1 Component design tests
10.3.2 Periodic tests
10.3.2.1 Millivolt testing
10.3.2.3 High current testing
10.3.2.3.1 Examples
11 Ground electrodes
11.1 Pole grounds
11.2 System neutral
11.3 Overhead groundwire (OHGW)
11.4 Ground rods
11.5 Measuring devices
12 Bibliography