I've been an electrician
around a decade now, and while most of the people I've worked with have been professional
, professionalism is not always the rule. Robert Heinlein
: "Never underestimate the power of human stupidity
." Below lies the proof.
Electricians sometimes like to work after work to pick up extra cash. In the trade, these are known as 'side jobs' as opposed to the day job that pays the bills and provides the health insurance
. One day a friend got a call from an anxious homeowner
. Seems the house was nearing completion and the lights wouldn't come on. So Tim said, okay, I'll come look at the job. In the trades, it's often wise to look before you leap
, as once in a while that will save you from stepping in something deep.
Tim arrived and everything looked sort of normal, except none of the lights worked. Owner couldn't understand it either, so Tim went digging. He found one wire in the light switch box
, one in the box that fed the light. A quick continuity
test determined that the previous 'electrician
' had indeed run a wire from light to switch, but had neglected to feed them from the panel. In fact, all of the lights had been run that way. Electricity does not conduct itself, so this presented a problem. Particularly as the walls had been finished. Tim asked if the walls had been inspected
. They had not, in fact there wasn't even a permit
. That is also a problem because the inspector can and will require you tear off the drywall so he can inspect the wires before he'll provide an occupancy permit
Tim chose that moment to inquire as to the fate of the previous 'electrician'. It seems he'd met an unfortunate end
. It took some digging, but the story was this. He wanted to get power into the new house, presumably to run some tool
s and perhaps his radio
. That's nothing unusual in itself, temporary power
has its own section of the National Electric Code
to see that such things are done safely. Unfortunately, in order to know the code, you must first read
it. It was in this step that things broke down.
Brain Dead Electric, as I shall call him, ran some romex cable over to a neighboring house and landed it in their working panel. Except, he didn't land the wire on a circuit breaker
as you would expect. He landed it on the main lug
s, which gave him no protection at all. In fact, he landed the neutral
on one of the two hot leads, so both the hot and grounded conductors were live.
Next Brain Dead returns to the newer house and lands the other end of his wire in the new electrical panel, only this time he does it 'right' and puts the black wire on the hot bus, and the white on the neutral. The way he should have done the other building.
Now article 250 of the National Electric Code specifies that the grounded and grounding conductors shall be bonded at the first means of disconnect, and that a grounding conductor shall be connected to the grounding system. That means the grounding conductor may be bonded to building steel (if grounded), an underground metal water (not gas!) pipe, and/or an additional grounding electrode
system. In Ohio, which has good, moist soil an eight foot ground rod is enough. So Brain Dead drove the ground rod and ran his grounding conductor, which was #6 bare copper
wire. So he grabbed his grounding acorn, the grounding conductor, and then reached for the ground rod
, which closed the circuit
He experienced a brief, shining moment.
When it rains, it shorts
If you have ever visited a shopping mall
you probably didn't notice any of the many light pole
s lighting your car keys as you struggled with your Christmas Presents
. I've put in a few of those in my day. The poles are fed underground through a network
s, usually made of PVC
and controlled by a series of contactor
s, with multiple circuits controlled by a photocell
Now, anyone who has worked with underground piping for any length of time knows that the pipes fill with water
. Okay, you may have noticed that plumber
s use PVC conduit all the time, and their pipe doesn't leak. But plumbers do things differently than electricians. Plumbers may sand the end of a connection, and they always clean it, plus do a lot of careful prep before they glue two pipes together. Then they take an air pump
and pressurize the line to 60 PSI or so and look for leaks. Fix said leaks and redo until the piping system will hold 80 PSI for an hour. It has to, otherwise it won't pass inspection
. Do all that and your pipe won't leak either. Plus, supply pipes are kept full of clean water, which pushes back. Me, I don't need to hold water. I need to conduct wire, and the THHN/THWN or XHHW wire I usually pull doesn't care if it's in a lake
. Keep mud and dirt out of the pipe, try to keep the ends clean, glue it and throw it in the trench
is all that's required to light your world.
Which is why my pipes all fill with water. Of course, everyone knows that. The NEC specifies that underground conduits shall be brought above ground level before entering an underground location. That's to keep the water below ground, and outside the building. An alternative is to install a seal off
, a kind of fitting that allows you plug everything around a wire. They're expensive, but mighty useful, particularly in locations where there is an explosion
Unfortunately, the people who ran the underground in this mall did neither. The ran their pipes straight into the electrical room which happened to be in the basement. With the pipes sloping downhill and entering right above a wall of contactors. That worked fine until we got a good spring rain, which does happen in Ohio. The heavens parted, the pipes filled. And the water ran downhill into $25,000 worth of switchgear
It gets worse.
On another job the foreman tried to be a little smarter. You see, he knew that the pipes filled water. And he'd pulled in a bunch of 750 KCM feeders-- big, stiff wires that cost multiple dollars per foot. So he decided to block the incoming water; by filling the pipes with concrete
. Right around the wires. Only, if you've poured concrete you know that it shrinks as it dries. Not much, but enough to prevent a good seal. Once again the rains came, and there was a mighty boom from five figures worth of switchgear. And the big, expensive wires were damaged as well.
The normal repair for that sort of thing is to pull in new wires, if there isn't enough left to splice
. Only these pipes had been filled with concrete, so the service man got to start over, using a directional bore
contributed an anecdote
of his own. So here it is.
At UNLV, one of our major networking switch
rooms is in the basement of a building that happens to by coincidence house the President
on the top floor. A lot of 4" conduit
comes in to the basement of this building, but because it's ll low-voltage
cable and fiber optic
s, the conduit does not come above ground before entering the basement. There's also a large ramp that opens onto a basement door, at the bottom of which is a man hole
for the junction vault
of said conduit. When it rains, which is mercifully rare in Vegas, the basement floods through the conduit. The building's transformer
is located very near to the spot the conduit enters the basement. (TM warns that transformers do go boom, and that's really bad).
When it rains, facilities maintenance
won't throw the circuit breaker
, because they don't want to turn off the President's
power, so one of our techs runs out and does it. On occasion he has to hop between highspots and office furniture
when it's been raining especially heavily.
The Mismeasure of a Man
Once there was a factory
full of conveyor
s and presses and more, and it produced widgets. All of this was powered by electricity, and so it had a honkin' big electrical service
. Which meant that the plant that made widgets paid a pretty substantial electric bill
One day the electric company got the idea that it would be cheaper if they didn't have to send someone
out to read the electric meter
. This being the computer age, the decided to automate the process, and put in a modem
so they could simply dial in and read the meter from the office. That in turn required a phone line
So the power company contacted a large and famous telecommunications
company which shall remain nameless. And they sent out a man to install the phone line.
Now this linemen came out to look at the job, and realized what he had to do, to drill a hole in the aluminum siding
of the factory to bring in the phone line right at the power meter. Only, he didn't have a tape measure
. But he did have feet
, and so he used his feet to pace off the correct distance from the door. Being a conscientious sort, he paced the distance off twice. And then he went outside to drill a wee little hole so he could bring the new phone line inside.
So he paced off the distance, twice, and then put a bit in his drill
. And he drilled through the siding. Only, he wasn't sure he was through. So he installed a longer bit, one two feet long. And then he drilled onward. finally hitting something solid. He smiled, realizing that if he got through this one last thing, he'd finally be inside the building. So he drilled on, and got through. Of course, when you finally drill through something, the drill often goes a bit farther before your gather it in. His did too, continuing onward until it struck something.
And there was light.
With the light came the sound of thunder
, with smoke and flames. Instantly all the conveyors and presses of the factory ground to a complete halt. The plant's chief engineer, who happened to be standing in the gear room at the time, suffered an involuntary bowel release
I don't blame him. Trust me, that was no small boom. M-80
s are pikers compared to that much electricity.
My friend Chris got the emergency service call. When he arrived at the plant, he was met by a still fragrant chief engineer, the plant manager and a man from a telecommunications company. That man was wearing a melted sweater. holding a drill whose bit drooped like it needed viagra and whose face resembled Al Jolson in The Jazz Singer. In short, he looked like Wile E. Coyote on a bad day.
There was a big, black spot on the side of the building.
Inside matters looked worse. The drill bit had indeed missed the meter location, but had penetrated directly into the back of a piece of 2,000 ampere
switchgear setting over a half meter inside the bulding. Two thousand amps is a LOT of power, capable of doing real damage. Upon penetrating the gear, the bit had gone on, to strike the busbar
, and for a brief, shining moment, became a grounding conductor
Now the NEC specifies that panelboards and switchgear be constructed so as 'to contain any explosion likely to occur inside", and for the most part it had. Of course, the back panel had served as a ground, and it had mostly melted. Things were scorched. everywhere, and theire were little droplets of congealing metal. And a whole lot of soot
Chris peeled his jaw off the ground, and began to investigate, noting the various pieces that had been turned into instant junk.
The telecommunications company employee in blackface
handed Chris his cellphone. It was a senior executive
at said large, famous and unnamed telecommunications giant. Because their employee had created this carnage, the unnamed mega-corp was now liable for the repairs. And
the lost production
. "You're going to have the plant up in one or two hours, right?"
Chris laughed, loudly and uproariously. While anyone can run to their local hardware store
and pick up a 200 amp panel, switchgear above 1,000 amperes is all custom built
. You can't just pick it up, you have to order it, and then it has to be assembled. This gear was totalled. He wasn't even sure the wire feeding it could be saved, along with various other pieces of equipment. He did some quick calcualtions. "More like two weeks," he explained.
The senior executive from the telecommunications giant, seemed upset to hear this. "How come it's going to take so long?"
"Because your dumb ass lineman there blew up fifty thousand dollars worth of custom built equipment, and I'm not sure how quickly Square D can make it, much less ship it here."
At that the soon-to-be former employee of a major telecommunications giant that shall remain nameless, jutted out his blackened chin and pointed his half melted drill with the drooping drill bit at Chris and asked: "Who're you calling a dumb ass?"
if you've been to the zoo lately you might notice that the animals aren't kept in cages, but in more natural environments that resemble (so far as possible) the animal's native environment. For a lot of creatures, a low fence is all that's required.
Big, potentially dangerous animals, like polar bears, are kept somewhat differently. Modern zoos use a big pit with a steep wall to keep the exhibit from eating the patrons. A deep trench between you and Yogi is (usually) more than enough to keep him from stealing your picnic basket.
One electrical contractor won the job of running some new power for a zoo. The project specifications called for all underground conduit to be rigid metallic conduit. That's pretty heavy duty stuff, made of mild steel with walls an eighth inch think. Rigid is strong and heavy.
But it's also expensive and time consuming to install. Rigid is threaded, and screws together, which means on a big job you have to manually thread any pipe you've cut. So the contractor elected to defy the specs and installed PVC conduit.
Really, the specs offered no benefit. Rigid is strong stuff, but it's steel, and even galvanized steel eventually rusts. Bury the PVC in concrete and you'll get a raceway that can't be penetrated by the odd pickaxe and will last forever. But a spec is a spec, and not following the specs can force you to replace every single thing you've done.
Still, they would have gotten away with it. The dug a nice, three foot deep trench, and buried the stuff. Except they forgot about all those pesky pits needed to safely contain Tony the Tiger. Those went fifteen feet deep, right through all that plastic pipe. Worse, Mr. Zookeeper and the construction manager was there to see how blatantly their spec book had been flouted.
So they ripped up every single inch, and re-installed it in rigid. Which goes to prove that doing it right the first time is the best way to make money.
If you liked these stories, buy beer for a building inspector of whatever trade. Those guys have some stories to tell, and the stories themselves justify what they do. And I reserve the right to add stories to this node, as particularly juicy bits become known to me.