book reviews

Electrical Safety Books

The Art and Science of Lightning Protection
by Martin A. Uman
Cambridge University Press, 2008, 240 pages


M artin Uman has written lightning books on several levels, from a small nipper called All About Lightning to the shockingly expensive Lightning: Physics and Effects with Vladimir Rakov. Although many of the same diagrams appear in all three books, they're for different audiences. This intermediate-level one is much cheaper than the physics book, but deals mostly with practical phenomena such as surge protectors and the design and placement of lightning rods on structures and power lines, relating the latter to NFPA and IEC requirements. It's a light introductory text, written at a high school/undergraduate level, and lacks the details about the technology that you would find in, say, the NEC (see at right).

Uman also tries to debunk several interesting myths about lightning rods, such as Franklin's original idea that pointy rods are better. It may be true, as the author says, that pointy rods don't get struck as often. But this is arguably irrelevant: what's more important is whether the structure underneath is protected more. So far, as Uman makes clear, the jury is out. There is also the implicit assumption in some chapters that lightning energy is direct current. This, of course, is not really true: lightning transients are mostly LF/VLF radio frequency phenomena, which introduces subtle changes in their behavior. The author's more advanced books presumably take these differences more into account.

Although I learned a few things from this book, I was struck by the lack of scientific information about lightning. The book contains grayscale photos of various wires and lightning rod configurations, but the photos of lightning itself and of objects struck by lightning are of poor quality. There is also very little practical information, like how to select or design a good lightning arrestor. It's a good general introduction to lightning safety, but if you're serious about protecting things against lightning, or if you're interested in lightning as an atmospheric phenomenon, you're gonna have to pay a bunch more money.

Practical Electrical Wiring, 19th Edition
Residential, Farm, Commercial & Industrial
Herbert P. Richter and Frederic P. Hartwell


A summary of the requirements for electrical wiring in the 2005 National Electrical Code (NEC), in a readable, narrative format. Check the local codes before buying this book; some locations only allow licensed electricians to do any electrical work. Intended to be used alongside a copy of the NEC. This book clarifies the NEC's rules and explains the reasons for them, as well as safety practices for electrical work, many of which are not obvious. For example, many people think that thinner wires can be used for lower voltages (such as from batteries). You might also think that a rating of 140° for wire means that it can be used at ambient temperatures up to 140°. This book will help you understand why both of those beliefs are false.

Divided into three sections: wiring principles, residential and farm wiring, and commercial and industrial wiring. Has numerous photographs and diagrams. The writers sometimes drift off topic and discuss wiring and construction techniques not specifically addressed by the code. Even so, this book is a much easier way to learn what the code requires than by reading the comparatively dry and formal NEC.

 nov 19, 2011

Codes for Homeowners
Bruce Barker


I f you've ever bought a house, you know the general rule: inspectors will miss code violations whey you buy, but find them when you sell. That means you have to know the building and electrical codes yourself. This Black&Decker book is a brief, illustrated summary of the International Residential Code, which many areas base their building codes on. It also has a quick chapter on the NEC, but for that you're better off with The Complete Guide to Wiring. An awful lot has been left out, but by presenting only the highlights, Barker makes it easier to remember them. And you'll be aware of what kinds of things to look for when you do it yourself or hire a contractor. You'd be amazed how many contractors ignore the code and just slap things in with lots of glue and duct tape. If you don't catch it, by the time you're ready to sell, the contractor will be in prison somewhere and you'll be the one who pays the price.

Apr 06, 2014