Wiring a House

338 Pages·2010·24.95 MB·English

by  Rex Cauldwell

rEvisEd and updatEd

-
builder tested code approved
Wiring a House
4th Edition
Rex Cauldwell
Wiring
a House

Wiring
a House
4th Edition
Rex cauldwell
T
Text © 2007 by Rex Cauldwell
Photographs © 2002 and revised 2007 by Rex Cauldwell
Illustrations © 2002 and revised 2009 by The Taunton Press, Inc.
All rights reserved.
Pp
The Taunton Press, Inc., 63 South Main Street,
PO Box 5506, Newtown, CT 06470-5506
e-mail: [email protected]
Copy editor: Seth Reichgott
Indexer: Jay Kreider
Technical Reviewer: Cliff Popejoy
Jacket/Cover design: Alexander Isley, Inc.
Interior design: Lori Wendin
Layout: Cathy Cassidy
Illustrator: Gayle Rolfe
Photographers: Rex Cauldwell unless otherwise noted
For Pros/By Pros® is a trademark of The Taunton Press, Inc.,
registered in the U.S. Patent and Trademark Office.
Library of Congress Cataloging-in-Publication Data
Cauldwell, Rex.
Wiring a house / Rex Cauldwell. -- 4th ed.
p. cm.
Includes index.
E-Book ISBN 978-1-62113-048-2
1. Electric wiring, Interior. 2. Dwellings--Electric equipment. I. Title.
TK3285.C38 2009
621.319’24--dc22
2009009136
Printed in the United States of America
10 9 8 7 6 5 4 3 2 1
The following manufacturers/names appearing in Wiring a House are trademarks: 3M®,
Black & Decker®, Bosch®, Bryant®, Burndy®, Carlon®, Cooper®, DeWALT®, EZ Wire®,
Fluke®, Gardner Bender®, Gen/Tran®, Greenlee® Nail Eater II™, Hubbell®, Hunter®,
Ideal®, InSinkErator®, Klein®, Louisville®, Lutron®, Magnus®, Makita®, Romex™,
Scotch®, Siemens®, Simpson 260®, SouthWire®, Square D QO®, TayMac®, Teflon®,
Torx®, UL®
About Your Safety: Working with electricity is inherently dangerous. Using hand or power tools improperly
or ignoring safety practices can also lead to permanent injury or even death. What is safe for one person under
certain cir cum stances may not be safe for you under different circumstances. Don’t try anything you learn
about here (or elsewhere) unless you’re certain it is safe for you. Please keep safety foremost in your mind.
acknowledgments
No one person creates a book. It is the accumulation
of many hands and minds. I would like to thank
Julie Trelstad, who guided me through the
conception of the original edition many years ago, and all
the people at Taunton who have worked so hard to make this
book the great success that it has been over the years.
It should be noted that a work of this kind is very
technical, and it is very easy for errors to slip by editors
even though a great deal of effort has been taken to find
such. If you note any problems, have questions, or would
like something added or changed, you can email me at
[email protected]. It should also be noted that the way
houses are wired on the East Coast may not be the same as
on the West Coast and that all areas do not adopt the same
exact code. Even under the NEC, I have to wire differently
in each county I work in.
Many companies helped with this book by providing
photographic material and technical information about
their products. I would like to give heartfelt thanks for
their help to Jim Gregorec of Ideal Industries, Inc.; Vivian
Beaulieu of Marchant and Field; Ben Bird of Certified
Insulated Products; Doug Kirk of King Technology, Siemens;
Constance Malenfont of TayMac Corp.; Jean Miskimon of
DeWALT public relations; M. F. Reed of Tytewadd Power
Filters; and Jay Thomas of AFC Cable Systems. I would
also like to thank the good people at Carlon®; Bussman;
Greenlee Textron, Inc.; Hunter® Fan Company; Hubbell®
Incorporated; Lutron®; Magnus® Industries, Inc.; and
Technology Research Corp.
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Contents
| Preface to the Revised edition 2
1 | The Basics 6
How Electricity Flows P. 8 | A Residential Electrical
System P. 13 | Wire Gauges P. 15 | The Wire We Use P. 23 |
Conduit Systems P. 31
2 | Tools of the Trade 34
General Tools P. 36 | AC-Powered Tools P. 44 | Cordless Tools P. 50 |
Specialized Tools P. 53
3 | The Service entrance 58
Buried or Aerial Service P. 60 | Calculating Amps, Choosing Cable P. 60 |
Locating the Meter Base P. 66 | Buried Service Entrance P. 70 | Aerial Service
Entrance P. 71 | Connecting Meter Base to Panel P. 78
4 | Panels and Subpanels 84
Elements of the Main Panel P. 86 | Picking a Panel P. 88 | Mounting
a Panel P. 90 | Bringing Cables into the Panel P. 96 | Subpanels P. 99 |
Balancing the Load P. 106
5 | The art of Grounding 108
A Grounding/Bonding System P. 110 | Protection through Grounding P. 112 |
Choosing Grounding Materials P. 115 | A Low-Resistance Panel-to-Earth
Ground P. 118 | What Needs Grounding P. 123
6 | wiring Room by Room 132
Outlet Box Design Location P. 134 | Pulling Cable in New Construction P. 147 |
Routing Wires in Renovation Work P. 157
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7 | Fuses and circuit Breakers 164
Fuses P. 166 | Circuit Breakers P. 169
8 | Ground-Fault circuit Interrupters 176
How a GFCI Works P. 178 | Ground-Fault Protection P. 184 |
Testing GFCIs P. 191 | Portable GFCIs P. 192
9 | arc-Fault circuit Interrupters 196
What Is an Arc Fault? P. 198 | Wiring AFCIs P. 201 | Troubleshooting
an AFCI Circuit P. 203
10 | Receptacles and Boxes 206
Receptacle Boxes P. 207 | Receptacles P. 217 | Polarity P. 221 |
Wiring and Installation P. 223
11 | Switches 232
Switch Boxes P. 234 | Types of Switches P. 239 | Light Dimmers P. 248
12 | wiring Fixtures 254
Choose the Right Box P. 255 | Incandescent Lights P. 258 |
Fluorescent Lights P. 259 | Ceiling Fans P. 261 | Smoke Detectors P. 268 |
Track Lighting P. 269 | Outdoor Light Fixtures P. 270 | Recessed Lights P. 274
13 | wiring appliances 276
Kitchen Appliances P. 277 | Baseboard Heaters P. 282 | Electric Wall
Heaters P. 286 | Utility-Room Appliances P. 287 | Submersible Pumps P. 291 |
Whirlpool Tubs and Spas P. 293
14 | lightning and Surge Protection 294
Induced Voltage P. 296 | Utility and In-House Surge Creators P. 297 |
Phone and Coaxial Cable Protection P. 306 | Protecting Pumps P. 308
15 | Standby Generators 312
History of Incorrect Connections P. 313 | Transfer-Switch Style P. 314 |
From Generator to Switch P. 319 | Picking a Generator P. 321 |
Automatic Generators P. 325
| Index 326
Preface to
the Revised
Edition
his new edition takes into consideration all of the latest
T
code changes. If you haven’t wired a house in a decade or
two, there are a few code changes you should be aware of.
(Note that states can adopt codes at different times and
may exempt sections they don’t agree with.)
One change was in marking the white insulated wire in switch
legs. At the time Wiring a House was originally written, code did
not require the installer to indicate whether a white insulated
wire, such as a traveler in a 3- or 4-way switching circuit, was not
a neutral, or whether a common switch was using a white wire for
its incoming power. Code now requires the white insulated wire
to be taped (any tape color except white, gray, or green) to make
sure you know that it is not a neutral.
There is the new rule on bathroom receptacles. Now you can
put a whirlpool tub, a bath heater, a heated towel rack, or bath
lights on a single bathroom receptacle circuit as long as that
circuit is not overloaded and stays in that one bath.
Common 125-volt 15- and 20-amp circuits in outbuildings,
like workshops or sheds, need GFCI protection. The wiring to the
outbuilding (multicircuit) should be done with four conductors
with an added ground rod at the panel.
To keep children from grabbing appliance cords and pulling
the appliance down onto themselves, all countertop receptacles
are now required to be above the countertop and cannot be
installed on a horizontal surface. Exceptions are made for
peninsulas and islands designed for handicapped persons.
Installers are now allowed to use nonmetallic (NM) cable in
residential installations at any grade level, including basements
and attics. Also, common 15- and 20-amp 125-volt receptacles
are now required to be tamper resistant assuming most of the populace would prefer to
(shutters built into the receptacle). AFCI wire the cheapest way possible no matter what
requirements have now evolved to encompass I suggested. So to all those who have calluses
the entire house except in GFCI areas, such as on your thumbs from turning pages, I dedicate
garages, kitchens, baths, and laundries. And this list to you.
when you install these same receptacles in wet
• Splices outside must use silicone-filled wire
and damp locations (such as outdoors) they
connectors. Buy them prefilled, or fill them
must now be rated weather resistant (special
yourselves.
receptacles)—even GFCIs. You might want
to verify that your locale has adopted these • A subpanel is to have its own main breaker.
changes before you wire.
• A n outside 125-volt receptacle, if not a
All 15-amp and 20-amp 125-volt receptacles
GFCI receptacle, must be of the heavy-duty
installed outside (you are required to have one
type (around $3 to $5), preferably nylon.
in the front and one in the back) must utilize
This is to prevent it from becoming cracked
waterproof covers that keep the receptacle
or broken, as happens when heavy-duty
waterproof even when a cord is inserted.
extension cords are wiggled in them.
above code • Do not put the overhead bath light on the
Above Code is my way of ensuring that the load side of a GFCI.
homeowner has a safe, high-quality, trouble-
• Smoke alarms—For new installations, re-
free, long-lived electrical installation. An
member that an AFCI will cut off power to
example of using Above Code is in wiring
the bedroom alarms if the AFCI trips due to
bathroom receptacles. If you were to simply
a fire, arc, or overload. Verify that all your
“meet code,” you could load up a bath
smoke alarms have battery backup and that
receptacle circuit with the lights, fan, heater,
the batteries are fresh.
and so on. A single hair dryer on a low setting
would wind up kicking the breaker and leaving • Wire gauge—Use nothing but 12-gauge
you in the dark. In fact, you could even put cable for all the 125-volt receptacle and
the bath lights on the GFCI circuit so that the switch wiring with the following excep-
lights would go out when the GFCI tripped and tions. If you are on a budget, you can use
you would literally be walking on a wet bath 14 gauge on the three-way lighting cir-
floor in the dark—and all by code. My Above cuits due to the extreme cost of the cable.
Code system shows you how a bath should This means that all the 14-gauge three-
be wired so that doesn’t happen. In addition, way lighting is to be kept away from the
my system tells you how to wire better, what 12-gauge cable and on a 15-amp circuit. If
products to buy, and which ones to avoid. you have the smoke alarms on their own
The following list is dedicated to all those circuits, you can use 14-gauge wire.
who have requested a singular list of the
• Each bathroom 20-amp, 125-volt recepta-
Above Code sections of the book so you
cle will have a dedicated GFCI circuit with
wouldn’t have to thumb through and write
nothing else on that circuit.
them all down—as well as some common-
sense code requirements. I didn’t previously • Service conductors should be copper. This
do this because I really didn’t expect my makes for easier wiring, as they can be two
method of wiring to become so popular— gauge sizes smaller than aluminum.