Thursday, April 17, 2014

Time to Rewire?

When is it time to rewire? I've noticed that the oldest wiring method, known as knob and tube, has taken quite a few hard knocks to its reputation. Of course, it doesn't have an equipment ground, and since it's considered to be an air cooled method, it can't be covered with thermal insulation (be careful when insulating the attic). Many insurance companies don't like to cover homes where it is still in use. But by far, the worst wire I've ever seen are the early sheathed cables that replaced it in the 1930's.

The insulating material in this product was Vulcanized rubber covered with cloth fiber, often with an over-wrap of craft paper, all packaged neatly in more paper and cloth, then impregnated with paraffin wax or some sort of bituminous mixture. Can anyone say "light it up"?  Sounds a lot like a candle to me. Some electricians refer to it as "crumble wire" because after the rubber hardens and the cloth dry rots, the insulation falls off leaving the copper wire exposed. I'd say in most cases that happened about three decades ago.

The crumbly stuff burns nicely, too, and unlike modern wire insulation, it "supports combustion." That means that once it lights up, it keeps burning provided it gets enough air. As an apprentice electrician, I remember the horror of balancing on the top of of a ladder to make up a live light fixture connection to this old stuff. The tiny ensuing spark ignited the "insulation." I pondered the relative dangers of blowing on the flame to extinguish it:

 "Hmmm... increased air flow might accelerate combustion and make this problem a whole lot worse. On the other hand, blowing on birthday candles usually puts them out ... I could spit on it if my mouth wasn't so dry. I wonder if the boss will let me take a lunch today?"

 I blew on it. It went out. The warehouse manager declined to rewire:

"Hey Kid, that's what insurance and fire alarms are for. Now, gettoutta here."

This is a picture of crumble wire, still in service in a bathroom light switch. Inspires confidence, doesn't it? I think the client only wanted to replace the broken switch. I'm sure glad she changed her mind when she saw what was behind the cover plate.  No worries now. It's all rewired with its own heavy-duty circuit, and a GFCI outlet.

The homeowner really didn't want us to look at any of the other wires in the house.  Ignorance is bliss, and usually better on the budget. She passed on our offer for an estimate to install interconnected household smoke detectors. I still wake in the middle of the night, sweaty after the nightmares I continue to have. PTSD? At least her kids are all grown up and away in college now.  Otherwise, I'd exhibit the poor business skills that have kept me driving a 15 year old van and offer to do it at cost.  Darn conscience.

Tuesday, April 8, 2014

I Did it Myself, Charlie! Saved a Bundle!

Danger is knowing just enough to get the job done. Here's a quick one:

What do you do with that prehistoric service cable that once powered the old electric range? Hmmm (Louie is scratching his beard, his mental wheels spinning furiously). It's 75 feet of copper. One might recycle it and make a few bucks. Then again, we might "repurpose" the thing. It's all electrical, right? Just remember to cut off the spare wire in that NM cable, use duct tape to make it nice and neat. Now with 50 amps to play with, the microwave, toaster, refrigerator and washing machine will finally work all together!

Sorry,  the picture should be clearer. I took it sitting in the dirt in a crawl space with lots of loose wire ends hanging from the joists overhead.

"Are these wires still live?" I talk to myself a lot because I don't have any friends and I'm the only one who really "understands" me.  "Nah - no one would be that careless," I reassured myself.

Then I saw this atrocity and froze in place. The blur you see is my uncontrollable shaking due to a realization that the exposed wire just three inches from my forehead was probably still on. I lost my roll of electrical tape somewhere 17 feet back as I crawled on hands and knees, away from the light, fresh air, freedom and Oreo cookies.

Sometimes I really hate my job, and when I get home, I kiss the four kids because I'm so glad the day is over and we can watch old Disney movies together. I can take a shower. Too many electrical workers don't get to do that when the day is done. Then I yell at the brats for not taking out the trash, mopping the floors, and fixing that damned leak in the roof. We all laugh. Seriously, though, my life is dangerous enough,  and I think it's only fair that one of them shows a little appreciation, gets up there, or empties the trash, maybe. Louie will fix the roof -  if I can find him.

For those not sure of what it is they're looking at - the yellow things are modern wires used for what I like to call a heavy-duty circuit - that's 20 amperes, maximum. The brown "stick" they're duct-taped to is an ancient cable once used to power an electric range. It was still attached to a 50 amp circuit breaker at the other end - just a little too big to protect sweet little 20 amp wires. I know the genius who came up with this idea cut off the grounds because the old cable didn't-have-one.

I'll fix this. But there's still lots of work to be done. A man's gotta do what a man's gotta do. When life gives you lemons, the world is aurulent and pussilanimous and we make beverages from it (honestly - I would not drink any of them). Pickles are sour. I like garlicy pickles and disobvious, hackneyed phrases, don't you?

Saturday, April 5, 2014

Fire Caused by Improper Wiring?

I used to think that when the fire department deemed a structure fire to be caused by defective wiring, it was an easy  "shot in the dark" assessment when there weren't any other obvious explanations like a fire bomb or failed alien invasion.  After all, most of the telling evidence would be burned and unrecognizable in the aftermath. Experts have to be able to give answers. I feel sorry for experts. I hope I never have to be an expert.

A few years ago I got a call to troubleshoot a number of non-functional lights and receptacles at a local tax preparation office. Despite the fact that all of the circuit breakers were still "on, "  lights to the restrooms and several outlets didn't work. It was proving to be a problem for both clients and employees, who were provided with a company flashlight to do their other usual occasional business, as the windows were boarded up in the rear of the establishment. The situation was not conducive to relaying confidence to potential clients, I'm certain.

Once on site, it became apparent to me that there had been a minor fire in the back rooms of the facility, a fact confirmed by the office manager. Yet, as the conflagration had been small and quickly controlled, the office had quickly reopened (it was tax season, after all!)

With its cover off, it was obvious that the panel in the office was only a subpanel - a remote. Somewhere in the building was a set of main service equipment. We located it in a spider-web shrouded cellar, for sure not visited recently by any human being. Service equipment is where the electric utility's wiring first enters a building. In this case, it was a lovely 200A disconnect switch from which emerged the smaller 100A cable to the subpanel I checked upstairs. Oddly, there was also a smaller 30A cable exiting the enclosure, landing in a large junction box.

Immediately obvious was that the 100 ampere-rated cable was not properly protected from over-current because it was connected to the 200A main breaker. But, after all, what's 100 amps between friends? What really drew my ire was that a set of thinner wires - the 30 amp rated ones - were inserted into the breaker as well.  These went to the junction box I'd noticed, and inside were connected to several even thinner wires that extended to the rear of the building. That's where the fire originated. My trusty electric meter verified that these cables were still energized.

So, the gist of the matter was that a few old  cables rated for a maximum of 15 amps in younger days was being "protected" by the 200 amp circuit breaker. Not to mention the double tapped connection at the main, or that the combination of aluminum and copper wires connected together in a damp basement results in galvanic corrosion.

No doubt, the combination of electric space heaters used to ease the chill of winter due to a non-functioning furnace or unpaid gas bill or an incipient plumbing leak from a chipped lavatory colluded to set off the fire in question. At its origin, the circuit was still "on" because the main breaker was providing power to the rest of the building - the lights were off because a wire had melted somewhere along the way awaiting another drip of water.

I resisted the urge to dash out of the dark pit, run through the crowded waiting room flapping my arms wildly shouting "Fire! Run like the wind!" I took a few pictures, instead. Crazy what cell phone cameras have done to us, isn't it? Technology has finally managed to co-opt the fundamental instinct for self-preservation. Really, who doesn't like pictures?

Oddly, I never noted the existence of an electric meter anywhere on the premises. Perhaps power was derived from solar panels or a gerbil-powered generator outside? Cheaper heating than natural gas, I'd say. While the client had been relayed all of this information with my profound concern for the gravity of the underlying hazards and an offer of a free estimate for corrective repairs (I declined to get involved in any temporary fixes), we never had a return call. I hope they broke the lease with the property owner, who, one must imagine, was devastated by the revelations and, at least, called another electrical contractor to make needed repairs. My evaluation was for the electricity and certain lunches in Congress.

What is my take-away lesson from all of this? First, I never assume anything.  Some electrical work is done by people better suited to selling soft pretzels on a street corner. It makes me shudder to remember a journeyman who "shut down" circuits by shorting the lines together instead of locating the proper breaker. He liked sparks, he said, and was rumored to have thrown a metal bar across a set of 13,000V utility lines from the window in a building he'd been working in. I think he's in real estate now; like six feet of it.

Another realization is that despite people's stated concerns for safety and the sanctity (blah blah blah) of life, most folks weigh it all in dollars and cents, especially when they're really giant corporations without mothers who might disapprove. When my calculation of risk exceeds anothers, I find it's best to just walk away and play with someone else. You know - I'm glad I did that time. Right, Mom?