Electric Wire Basics

Worker's compensation insurance covers on-the-job injuries. It covers medical expenses, compensation for time lost from work, and even retraining in a new vocation should impairment preclude the injured worker from continuing in the same field.

Worker's compensation insurance covers on-the-job injuries. It covers medical expenses, compensation for time lost from work, and even retraining in a new vocation should impairment preclude the injured worker from continuing in the same field. Some trades pay more for their insurance than others. That's because some are more risky. They have more accidents and, therefore, more claims. Here's a question: which of the following listed trades is the riskiest, thereby having the highest worker's compensation insurance rates? Heating, carpentry, plumbing, electrical or roofing?

You'll find the answer as you continue to read.

As we see it, electrical wiring is nothing more than a bunch of fancy extension cords. They run through walls, floors and ceilings connecting lights, plugs and switches to make our paths brighter and our lives easier.

For some shocking reason some folks are terrified of electricity.

Electricity should be dealt with carefully, but it doesn't have to be dangerous. Working with sheetmetal or glass can be a disaster. A minor accident can mean a serious laceration. With carpentry, a slip of the wrist can mean a smashed thumb - a fingernail gone forever. With roofing, one slip can mean injury or even death. With electricity - as long as the power has been turned off - there isn't much you can do to hurt yourself.

"Wiring Simplified" by Richter is easy to read and simple to understand. It contains lots of clear, well-thought-out illustrations. It's in its 39th edition and sells for under $10. We found it on the web at www.buildersbooksite.com, a website devoted to construction literature.

But before you begin reading, there are a few things that you should know about wire and wiring. First, there are three basic types:

The kind that comes in a flexible metal shield - BX. It is used for interior wiring where the wire will be exposed to human contact.

The kind where several strands are held together in a plastic shield - NM (nonmetallic). It is used for house wiring where hiding within walls, in attics and crawl spaces is desired. The kind that can be used underground - UF (underground feeder). This kind is used for direct burial underground. No conduit is needed.

BX wire is used where you might cause damage to an exposed wire - under a kitchen or bathroom cabinet, for example. Whereas nonmetallic wiring is fine for inside walls, it can be easily damaged if left exposed to human transgressions. Nonmetallic wire is no match for sharp knives, hot pots and tugging toddlers. BX, on the other hand, is encased in a hard, flexible metal shield that is nearly impenetrable. So, in walls you would use NM wire (Romex), and for interior wiring outside walls, BX is better. Be sure to check with your local building inspector. BX cannot be used outdoors and can be used only in short lengths indoors. For other jobs, outside-wall metal conduit must be used. Wiring with conduit requires several special tools and some experience. If NM, BX or UF wire won't do the job, call a professional.

UF wire is designed to be buried directly into the earth. No conduit. However, there is a major problem with all plastic wire - it is easily damaged. Landscape lighting, sprinkler wiring, and other outdoor electrical wiring travels subsurface. Tree, shrub, and flower planting, roto-tilling and other groundbreaking practices can damage wires near the surface. The building code suggests that all such wires be buried at least 18 inches below grade. We think a good rule of thumb is 2 feet or deeper.

Don't be afraid to break out a little plaster or wallboard to conceal wiring. There isn't anything more tacky than a shiny new electric fixture mounted on a wall connected to exposed wiring.

Wiring in a wall must be protected when it travels perpendicular to a wood framing member. For example: a wire that travels through a stud must be protected with a metal plate before the wallboard is installed. The plate protects the wire from things such as nails for picture-hanging.

So, which trade did you deem most dangerous? If you said roofing, you're right. By the way, worker's compensation insurance for electrical is among the lowest.

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If any of you has a helpful hint or tip that we can share with our readers we'd love to hear it.

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