A general overview of the use of utility distribution poles, including for electric supply and communications applications
Overhead Distribution Lines: Design and Applications provides information on the design and use of power and communication distribution lines. An excellent resource for those in the power and communication utilities industry, this book presents information on the physical characteristics of utility poles, overhead supply and communication cables, installation practices, joint-usage issues, and safety rules, including the National Electrical Safety Code (NESC), California-specific rules, and others. It describes how to select the proper poles for specific applications. The especially valuable final chapter provides examples showing how it all works in practice, providing a background allowing more effective use of related industry software.
Rather than delving into detailed design and installation techniques, this book serves as an overview for engineers and non-technical audiences alike. At the same time, it serves as a compendium of technical information not readily available elsewhere. This unique book:
- Offers an overview of pole structures, pole installation and maintenance, wires and cables, and cable installation and maintenance - with examples
- Provides information on national standards documents such as the National Electrical Safety Code (NESC), ANSI O5.1, California General Order 95, and more
- Explores the "sag–tension" relationship between wires and poles
- Includes appendices that cover properties of messenger strands, wireless attachments, solution of equations to determine sag, under uniform and point loads
Overhead Distribution Lines: Design and Applications offers readers an understanding of the basic principles and various issues related to electric supply and communications distribution lines. It is a valuable resource for utility engineers, as well as those without a technical background.
About the author
Preface
Dedication
Acknowledgements
Chapter 1 Introduction
1.1 Scope
1.2 Background
Chapter 2 Pole Structures
2.1 General
2.2 Wood Pole Strength
2.3 Loads
2.4 Embedment Depth
2.5 Guying
2.6 Column Buckling
2.7 Grounding and Bonding
Chapter 3 Pole Installation and Maintenance
3.1 Pole Placement
3.2 Guys and Anchor
3.3 Pole Maintenance
Chapter 4 Wires, Conductors and Cables
4.1 Categories
4.2 Messenger Wire/Strand
4.3 Electric Supply (Power) Cables
4.4 Communications Cables
4.5 Wireless Attachments
Chapter 5 Cable Installation
5.1 Conductor and Cable Placement
5.2 Lashing Operation
5.3 Overlashing
Chapter 6 Nesc® Requirements (Strength & Loading)
6.1 National Electrical Safety Code (Nesc)
6.2 Loading Requirements
6.3 Strength Requirements
6.4 Wire Tensions
6.5 Guyed Poles
6.6 Extreme Wind Loads (“60 Ft Limit”)
6.7 Allowable Deterioration
6.8 Overlashed Cables
6.9 Software Tools And Pole Loading Analysis
Chapter 7 Nesc® Requirements (Clearances)
7.1 Clearances
7.2 Clearance Zones
7.3 Clearances Above Surfaces and Buildings
7.4 Clearances Between Wires
7.5 Overlashed Cables
Chapter 8 Principles Of Wire Sag
8.1 Catenary
8.2 Initial and Final Sag
8.3 Sag – Tension Relationship
8.4 Determining Change in Sag (and Tension)
8.5 Ruling Span
8.6 Point Load
Chapter 9 General Order 95 (California)
9.1 General Order 95 (Go 95)
9.2 Loading Requirements
9.3 Strength Requirements
9.4 Clearances
Chapter 10 Examples
10.1 Purpose
10.2 Tangent Line
10.3 Line Angle
10.4 Line Angle – Buckling Consideration
10.5 Additional Attachment
10.6 Summary
Glossary
References
Appendix A Properties Of Messenger Strands
Appendix B Wireless Attachments
Appendix C Extreme Wind And Extreme Ice Loadings
Appendix D Solution Of Cubic Equation
Appendix E Point Load
E.1 Parabolic Model
E.2 Intersecting Straight Lines Model
Index
