Practical Electrical Wiring

532 Pages·1941·80.109 MB·English

by  H.P. Richter

LIBRARY
OF
PRACTICAL EI.JECTRICITY
•
PRACTICAL
ELECTRICAL WIRING
Residential, Farm, and Industrial
BASED ON THE 1940
NATIONAL ELECTRICAL CODE
BY
H.P. RICHTER
Member, International Association of Electrical
Inspectors, American Society of
Agricultural Engineers
SECOND EDITION
FOURTEENTH lMPHESSION
McGRAW-HILL BOOK COMPANY, !Ne . .
NEW YORK AND LONDON
1941
PRACTICAL ELECTRICAL WIRING
COPYRIGHT, 1939, 1941, BY THE
McGRAW-HILL BooK CoMPA.<'IY, INc.
PRINTED IN THE UNITED STATES OF AMERICA
All rights reserved. This book, or
parts thereof, may not be reproduced
in any form without permission of
the publishers.
PREFACE TO THE SECOND EDITION
The immediate acceptance and wide popularity which fol
lowed the publication of the first edition of this book have
prompted me to prepare this second edition.
Everything in the first edition has been retained, and some
new material added. The entire volume has been reconciled
with the new 1940 National Electrical Code, including the
tables in the Appendix, so that the reader is assured that he
is dealing with present-day methods and requirements .
•
H.P. RICHTER.
CANTON, OHIO,
February, 1941.
v

PREFA CE TO THE FIRST EDITION
In preparing this book it has been the author's aim to make
it simple enough for the beginner, yet complete enough so that
it will be of value also to those already engaged in electrical
work. It is intended to be, not a manual that merely recites
the methods used in wiring buildings for the use of electricity,
-but rather a book that explains the subject in such fashion
that the reader will learn both the way things are done and
why they are done in that particular way. Only in this manner
can the student master the subject so that he can solve his
own problems as they arise in actual practice, for no book
can possibly cover all the different problems that are likely to
arise.
Since this book is not intended to include the subject of
electrical engineering, only so many basic engineering data as
are essential have been included, and these so far as possible
have been boiled down to ABC proportions.
All methods shown are in strict accordance with the ational
Electrical Code, but no attempt has been made to include
a detailed explanation of all subjects covered by the Code.
The Code is written to include any and all cases that might
arise in wiring every type of structure from the smallest cottage
to the largest skyscraper; it covers ordinary wiring as well as
those things that come up only very rarely. The scope of this
book has been limited to the wiring of structures of limited
size and at ordinary voltages, under 600 volts. Skyscrapers
and steel mills and projects of similar size involve problems
that the student will not meet until long after he has mastered
the contents of this book.
The book consists of three parts:
Part 1 presents the fundamentals of electrical work; termi
nology; basic principles; the theory behind general practices.
vu
viii PREFACE TO THE FIRST EDITION
Part 2 deals with the actual wiring of residential buildings and
farms. Part 3 covers the actual wiring ·of nonresidential
buildings, such as stores, factories, schools, and similar
structures.
The author acknowledges with appreciation permission
to quote from "The Science of Seeing" by Matthew
Luckiesh and Frank K. Moss. Other books that he has
found helpful are listed in the Bibliography appearing at the
end of the text.
H. P. RICHTER.
1£VANS'l'ON, lLr,.,
November, 1939.
CONTENTS
PAGE
PREFACE TO THE SECOND EDITION v
PREFACE TO THE FIRST EDITION . Vll
PART 1. THEORY AND BASIC PRINCIPLES
CHAPTER
1. UNDERWRITERS AND CODES . . . . . . . . . . . . 3
2. ELECTRICITY: BASIC PRINCIPLES AND MEASUREMENTS. 12
3. TYPES OF CURRENT; POWER FACTOR; TRANSFORMERS. 28
4. BAsic DEVICES AND CIRcurrs 48
5. 0VERCURRENT DEVICES . . 66
w
6. TYPES AND SIZES OF IRES 76
7. SELECTION OF PROPER WIRE SIZES 94
8. WIRE CONNECTIONS AND JOINTS 102
9. THEORY OF GROUNDING ... 116
10. OUTLET AND SWITCH BOXES . 123
11. DIFFERENT WIRING METHODS 138
12. BRANCH CIRCUITS AND SERVICE ENTRANCE. 165
13. ADEQUACY. . . 190
14. Goon LIGHTING 200
15. RESIDENTIAL AND FARM MO'l~ORS. 227
PART 2. ACTUAL WIRING: RESIDENTIAL AND FARM
16. PLANNING AN INSTALLATION. . . . . . . . . . . 237
17. INS'l'ALLATION OF SERVICE ENTRANCE AND GROUND. 244
18. INSTALLATION OF SPECIFIC OUTLETS . . . . . . . 260
19. FINISHING: INSTALLATION OF Swl'l'CHES AND OTHER DEVICES 289
ix
x CONTENTS
CHAPTER PAGE
20. MJSCELl,ANEOUS WIRING 297
21. OLD w ORK. . 316
22. FARM WIRING 336
23. ISOLATED LIGHTING PLANTS 350
24. WIRING APARTMENT HOUSES. 357
25. CHANGES IN 1940 CODI!: WITH RESPECT TO WIRE 369
PART 3. ACTUAL WIRING: NONRESIDENTIAL PROJECTS
26. PLANNING NONRESIDENTIAL lNS'l'ALLATIONS 379
27. MisCEJ,LANEous PROBLEMS IN NoNRESIDEN'l'IAL WIRING. 402
28. NONRESIDENTIAL LIGHTING 413
29. WIRING FOR MOTORS . . 426
30. WIRING SCHOOLS AND CHURCHES. 454
31. \VIRING OFFICES 463
32. WIRING STORES 466
33. WIRING MISCELLANEOUS OCCUPANCIES 472
APPENDIX (CODE TABLES). 481
BIBLIOGRAPHY. 513
INDEX 515