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Electrical Wiring

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By Tim Carter
©1993-2010 Tim Carter

Summary: Electrical wiring is a job for a person with experience. You can start an electrical fire very easily if the wiring you install is not done to minimum national electric code standards.

Related Articles: arc fault circuit interrupters, new arc fault breakers, circuit interrupter manufacturers

DEAR TIM: Electrical wiring is in my near future as part of a bathroom remodeling job. I have to relocate an existing box that has three switches in it. In addition, I want to install new recessed lighting in the ceiling. There is attic space above the ceiling, so that should be easy. I have replaced outlets and switches before, but I wonder if I am getting past my skill level with this job. What would you do if you were me? What are the dangerous aspects of this job? Bob R., Erie, PA

DEAR BOB: Every aspect of this electrical wiring job is highly dangerous. Don't confuse the danger of working with electrical cables, wires and boxes that have yet to be connected to the circuit panel board with the hidden dangers of energized electrical wiring that can arc and overheat, causing a fire.

People die everyday from house fires caused by defective or improperly installed electrical wiring. If you are not 100-percent confident in exactly what needs to be done and how to do it to satisfy all applicable parts of the National Electrical Code, then hire a professional to do the job.

If you now have a sufficient respect for electrical wiring, that is a great thing. But if you decide to forge ahead and tackle the job, then I beg you to become well-educated in all parts of the job, so the wiring and fixtures are installed to code. There are many written and visual teaching aids available that can help with this vital training. You might even find a local vocational school that offers evening classes in residential electrical wiring.

The different cables entering this electrical box can confuse a rookie electrician. There are strict guidelines that govern how electrical wiring must be installed. PHOTO CREDIT: Tim Carter
The different cables entering this electrical box can confuse a rookie electrician. There are strict guidelines that govern how electrical wiring must be installed. PHOTO CREDIT: Tim Carter
The list of things you need to know about this small job is almost endless. To give you a small taste of how intricate and complex the knowledge base is about residential wiring, let's go over a few things:

First, you can't just put in any type of light fixture for your recessed lights. The metal housings come in different models, depending upon heat conditions. There may be no insulation in the attic now, but what happens if someone blows in insulation at a later date and covers a recessed lighting fixture not rated for direct contact with insulation? I'll tell you what happens - a fire. Insulation can trap heat in a fixture, and cause the fixture to get so hot, it melts the plastic insulation on the electrical cable and individual conductors. You can buy recessed light housings that can be covered with insulation, so find those and install them.

The size and type of the cables and wires you install is extremely critical. You may be tempted to work with 14-gauge wiring material, because it is easier to handle. Maybe a store clerk said it meets code. But what happens if the circuit you are working on is controlled by a 20-ampere circuit breaker? I'll tell you what might happen - a fire.

Circuit breakers are meant to protect wires, not people. A 14-gauge wire can overheat and catch fire before a 20-ampere circuit breaker will trip, cutting off the power. All of the wiring in a particular circuit must be matched to the size of the circuit breaker controlling the circuit.

Something as harmless as a cable staple is important. Hammer one too hard, and it can pierce the insulation on the cable and the individual conductors within the cable. Arcing can happen at a later date, which then starts a fire.

Installing wire nuts and twisting conductors the right way may seem intuitive, but if done improperly, these critical connections can be the source of electrical fires months or years from now. Every single aspect of the job is important, and you must be focused the entire time you work with all of the electrical components.

If you want to gain a new perspective for the potential fire hazards of simple residential electrical wiring, I urge you to stop by a local firehouse. Talk with a seasoned roughneck firefighter, district commander or perhaps the assistant fire chief. These individuals have seen what a simple electrical wiring mistake can do. In the worst cases, they may have had to zip up one of those dreadful plastic body bags and carry it to a waiting county vehicle.

I have seen the aftermath of several electrical fires, and the damage to property, life and spirit is horrific. Be sure the work you do, or that is done by a professional, is inspected. Do not assume everything is fine, as tiny mistakes can cause large fires.





Comments:

Bill Caisse
03 Dec 2007, 09:01
Added a bar counter top to my existing counter. My problem is I cannot add electrical outlets to this area since there is not enough wall area. Is there any products like strip electrical outlets that can be used?
AsktheBuilder
03 Dec 2007, 09:09
Yes! Go visit a real electrical supply house, not a home center.
Dan
22 Dec 2007, 13:06
Hey I have a question with the wiring. I'm wondering if I can use the same source for the lights in a room as the receptacles. In the end leading one source from the main source to each room. Or do lights need their own source and receptacles their own?
AsktheBuilder
22 Dec 2007, 13:36
Dan,
I do believe that the National Electric Code allows this. But many seasoned electricians will probably agree it is not a good practice. You should have two circuits feed a bedroom and split the receptacle load between the circuits.
Melissa
19 Jan 2008, 05:45
We have a 28 year old home we purchased two years ago. All the rooms are equipped with baseboard heaters. Since the home is rather large and open concepted, I find these appliances are rather inefficient in heating the space. Mind you we live in Canada and the winters have an effect on how we regulate the thermostats but we do keep all set at 68 degress.

My question is, one of the home centres is advertising 220V 2000W wall convection heaters which are compatible with any line voltage thermostat. Does this mean we could replace the existing baseboards with these new devices?

Thanks
AsktheBuilder
19 Jan 2008, 05:50
Melissa,
I can't really answer with confidence as I would need to inspect your home and its wiring, breakers and/or fuses, etc. You need to involve both heating and electrical professionals and have them evaluate what you have and if the units will really achieve your goals.
chritsopher
20 Jan 2008, 06:51
what is the the latest in electrical wiring
Frank
27 Jan 2008, 09:30
I changed my light and now the switch does not switch the light off!
I thought I remembered how the old light was wired but maybe I got something wrong? Two pipes coming out of the ceiling. One pipe has 2 reds and one green coming out of it, the other has 1 red, 1 green and 1 black. Originally the 3 reds from the two pipes went to the red of the light, the black went to the brown of the light and the two greens from the ceiling just connected to each other, without going to the old light. I did this for the new light and also tried all other possible combinations and the best I can get is that the light goes on, but the swtich does not switch the light off! Do you have any ideas?
AsktheBuilder
27 Jan 2008, 09:48
Frank,
It sounds like you are dealing with a ceiling fan light???? Go to their website for a wiring diagram that shows all of that spaghetti you are dealing with.
frank
27 Jan 2008, 09:57
Thanks for getting back. No, both the old and the new fixture are simple lights, with 1 brown, 1 blue and 1 green wire. The problem is in the two pipes coming out of the ceiling. Usually there is only one pipe with just three wires coming out. I have never seem two pipes, each with different wires. I think that one is for the light and the other has something to do with the switch and that, for this reason, they both need to have some wiring going to the light.

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