Table Of Content

Guide to Electrical Power Distribution Systems Sixth Edition i Tree of Electricity Transmission and Distribution PDL: Primary distribution lines, ✭ indicates location of transformer stations. ii Guide to Electrical Power Distribution Systems Sixth Edition Anthony J. Pansini, EE, PE Life Fellow IEEE, Sr. Member ASTM THE FAIRMONT PRESS, INC. iii Library of Congress Cataloging-in-Publication Data Pansini, Anthony J. Guide to electrical power distribution systems/Anthony J. Pansini.--6th ed. p. cm. Includes index. ISBN: 0-88173-505-1 (print) — 0-88173-506-X (electronic) 1. Electric power distribution. 2. Electric power transmission. I. Title. [TK3001.P284 2005] 621.319--dc22 2004056257 Guide to electrical power distribution systems, sixth edition/Anthony J. Pansini ©2005 by The Fairmont Press, Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. Published by The Fairmont Press, Inc. 700 Indian Trail Lilburn, GA 30047 tel: 770-925-9388; fax: 770-381-9865 http://www.fairmontpress.com Distributed by Marcel Dekker/CRC Press 2000 N.W. Corporate Blvd. Boca Raton, FL 33431 tel: 800-272-7737 http://www.crcpress.com Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 0-88173-505-1 (The Fairmont Press, Inc.) 0-8493-3666-X (Dekker/CRC Press) While every effort is made to provide dependable information, the publisher, authors, and editors cannot be held responsible for any errors or omissions. iv To my superiors, associates, colleagues, and subordinates, from whom—along the way— I learned much v This page intentionally left blank Contents Preface...................................................................................................ix Chapter 1. The Transmission and Distribution System....................................1 2. Conductor Supports .............................................................................. 3. Insulators and Conductors................................................................... 4. Line Equipment...................................................................................... 5. Overhead Construction......................................................................... 6. Underground Construction.................................................................. 7. Service Factors........................................................................................ 8. Substations............................................................................................... 9. Distribution Circuits, Cogeneration and Distributed Generation 10. Essentials of Electricity Appendix A. Insulation: Porcelain vs. Polymer......................................... Appendix B. Street Lighting, Constant Current Circuitry....................... Appendix C. The Grid Coordinate System, Tying Maps to Computers..................................................... Appendix D. United States and Metric Relationships.............................. Index..................................................................................................................... vii Figure P-1. Simplified schematic diagram of transition from regulated to deregulated supply systems. viii Preface to the Sixth Edition This edition continues the practice of updating its contents to re- flect changes affecting electric distribution systems. It continues its origi- nal role of providing information in a non or semi technical manner to persons working on such systems enabling them to perform their duties in an enlightened way. This contributes not only to a greater quality of production, but more importantly, with greater safety to themselves and the general public, the consumers they serve. While the effects of deregulation have been more pronounced on the generation and transmission components of the supply chain, it has also had an impact on the distribution system with its cogeneration and distributed generation features. Improvement in materials and methods continue to contribute to the economic and environmental betterment enjoyed by consumers. Predominant among these include the gradual replacement of heavier porcelain insulators with polymer (plastic) ones, the employment of insulated bucket vehicles making climbing with the use of spikes a lost art. Improvements in “solid” type insulation in cables, and more effi- cient machinery for placing them underground. Thus narrowing the economic differences between overhead and underground installations. The distribution system is the most visible part of the supply chain, and as such the most exposed to the critical observation of its users. It is, in many cases, the largest investment, maintenance and operation expense, and the object of interest to government, financial agencies, and “watch dog” associations of concerned citizens. As such, the desirability of knowing how and why it is so constituted becomes obvious. Distribution systems have also been affected by deregulation, although not in the same manner as transmission systems, Figure P-1 (opposite). Where additional transmission or generation was not avail- able or too great an expense to supply some additional loads, Distrib- uted Generation made its entry on Distribution Systems. Here, small generating units usually powered by small gas turbines (although other ix