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#58118 - 10/30/05 12:44 PM Chicago Tribune article...
DougW Offline
Member

Registered: 06/08/03
Posts: 1083
Loc: North Chicago, IL
Saw this in friday's tribune... thought I'd share.

 Quote:
Old wiring may come up short

By Mike McClintock
Special to the Tribune
Published October 28, 2005

Everyone has been through a blackout, when clocks stop, televisions go black and the array of machines that cool, heat, clean, wash and dry won't run.

It's always a little surprising because people expect electricity and wiring to work properly and indefinitely. When power lines topple, conditions are beyond your control. But problems also arise inside, usually due to one of the top electrical hazards identified by the Copper Development Association (CDA), a trade group that deals with residential electrical systems.

- Old wiring. Dated systems typically show their age with frayed wires, brittle wire insulation and faulty switches--one part of the system that can suffer mechanical breakdowns from years of being turned on and off.

Overall, the safety threshold for household wiring is about 40 years, according to the CDA. Properly installed wiring may be trouble-free longer than that but won't provide the safety or capacity specified in modern codes. If you haven't upgraded an older system, 40 years is certainly time for a checkup.

Most hazards are due to poor workmanship in the original installation but even more so to updating by homeowners and incompetent professionals, the CDA says. There is no periodic re-inspection procedure, and unsafe changes may not be discovered until a house is sold or improved in a way that requires a building permit.

If you find unexploded bombs like zip cord (small-gauge extension cord wire) buried in the wall, you need the electrician yesterday.

- Dated wire size. Decades ago, houses didn't use as much electricity as they do today. (The Department of Energy says energy use in homes has increased fourfold from the '50s to the '90s.)

The upshot is that many older homes have wiring designed to carry smaller electrical loads, typically 14 awg (American wire gauge), suited to handle 15 amps, the limit for then typical circuits.

If the sizes and numbers are puzzling, think of the garden-hose analogy: a large-diameter hose carries more water than a small one the same way a thicker wire carries more power than a thin one.

Unfortunately, the AWG system only adds to the confusion because of its inverse ratings: the larger the wire, the smaller the number. That means modern 10- or 12-gauge wiring is thicker than 14- or 16-gauge.

Size isn't significant with a garden hose; try to pour more water through a smaller diameter and it won't go. But the difference is crucial with wiring. If you try to carry more power through a smaller wire, it heats up, and that can cause trouble, including house fires.

Complete rewiring is a daunting project and requires a skilled electrician. But consider upgrading to 10- or 12-gauge in high-use areas such as kitchens and utility rooms. If you routinely pop circuit breakers, upgrading is essential.

- Inadequate circuits and outlets. Homes only 20 years old may be under-wired in another way--with minimal circuits and outlets that can't handle appliances and home office equipment. And when the system falls short, temporary extension cords can become permanent.

With breakers protecting branch circuits and outlets, even a limited layout generally proves more inconvenient than unsafe. Hazards are more likely to stem from the extension cords.

The best fix is a new circuit to power new outlets in heavy-demand areas. Sometimes an existing line can be split, creating two circuits, each with its own breaker.

- Too many extension cords. Many houses have tangles of extension cords ingeniously rigged from one outlet to a stunning amount of equipment. If only one or two appliances run at the same time there's no problem, and a breaker should trip if the load is excessive.

But as the CDA puts it, extension cords should seldom be needed in an adequately wired house. Tucked under carpeting they become a common cause of house fires. And to power appliances through extension cords, people often clip polarized plugs and grounding prongs, defeating basic safety features.

Aside from frays and cracks (those cords should be replaced immediately) the main telltale is heat, a sure sign of overloading.

Using a thicker cord will help--16 gauge or lower instead of 18 gauge. But upgrading with additional power, circuits and outlets is a more convenient and much safer solution.


While I can't argue with the main premise of the article (it'll be good for biz), running 10 as a standard to a 20A kitchen circuit? I could understand if it's 100' away, but c'mon.

Isn't the CDA the folks that would like us top live in copper houses - ie a copper industry promotion shop?

I love copper, but gimme a break.

[This message has been edited by DougW (edited 10-30-2005).]

[This message has been edited by DougW (edited 10-30-2005).]

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#58119 - 10/30/05 03:43 PM Re: Chicago Tribune article...
livetoride Offline
Member

Registered: 01/11/05
Posts: 109
Loc: san diego ca usa
Here in San Diego I have seen (last year) a complex feed from #10 service conductor with a 30A button fused (Edison) 2 circuit feeding each 2 BR units. The 90+ yr owner did not see why he should upgrade, as it has worked for him for 50+ yrs. I know it would be a nightmare to have periodic re inspections but if were feasible I would support it. Rod

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