From two reports that we've probably all read (one involving a woman in Las Vegas, the other involved a dog -- don't remember the city), we all know this is not an urban legend.
On my way up the hill to catch the subway, I happened by a lampost with a hot-pink piece of paper pasted on the traffic-light control box.
The word "ELECTROCUTION!" caught my eye and so, figuring it probably had to do with X-mas tree lights being strung across awnings, banisters, etc.
My first thought was someone had touched a faulty fairy-light string, gotten bitten and therefore was making this big deal about them. No big surprise considering how chintzy those light strings are.
It turns out that, according to the author, that some people have been shocked when they've walked over utility manholes or touched or leaned up against lamp-posts.
Too many of the lamposts in my fair city that I run across, have the access hatch covers in the bases missing and sometimes the jumble of wires has been pulled out and is spilling out on the sidewalk. Water (especially snow runoff) gets into these things often.
Five fire-engines visited my street corner last Saturday night to answer a call about flickering lights in my apartment building. Turns out a transformer vault in the street had caught fire.
The snow has since been shoveled and melted away so I took a look at the manhole in question. Con Edison had been doing work a few months ago and had laid a temporary cable coming out the manhole and down the gutter along the sidewalk while they cut up a slit in the street to replace a faulty underground cable.
Eventually they removed the feeder and patched up their work. So what I noticed today were holes and cracks in the patch, along the manhole. Probably a combination of road salt and melting snow that caused it to leak into the underground vault.
Wasn't the lady in Las Vegas killed as she stepped over an access hatch that was covering some wires with worn insulation? The dog that got killed (anyone remember where this was) happened to be standing on a similar metal cover and the owner didn't know what was going on when he/she saw their dog having convulsions.
Hmm....I guess ol' Tommy Edison's manhole covers are just another thing to dodge in addition to the usual piles of dog dung, people's expectorations and chewing gum so common on a New York City sidewalk....
arent the lamp posts grounded? Arent they grounded by just standing in the ground? we have all lamp posts grounded with a steel stripe or stuff like that, but shouldnt it be enough without as the post goes far into ground?
You'd think so. Maybe it's not a good enough ground (if there is any at all).
There was also a case that I read about a kid who got electrocuted when he was walking on a bridge...seems like he touched the metal railing or something.
I've seen lamp posts frequently being used as equipment grounding connections for movie shoots. Some posts even have a "cam-lock" connector set in the base in order for crews to use that hookup. Other crews I've seen use a giant "alligator clip" clamped to the edge of the access hatch.
About 20 or so years ago a man was electrocuted while waiting for a bus in Cleveland OH. The man stepped on a manhole cover that had a transformer that was no longer feeding anything but it was still recieving power and something went very wrong.
As one might expect the city got sued and this was front page news for awhile.
This is all from memory so the details may be off.
Yea Jim, that just happened a few months ago in Columbus. 9 year old boy on his way home from COSI (popular hands-on science center for children). Reports say investigators found 480 volts of electricity were sent through his body due to failed insulation on an old splice in the base of the light post. His family sued the City of Columbus back in November. Here are a couple of links to stories if you wish to read more. Too tragic to even think about. http://www.nbc4columbus.com/news/2224031/detail.html http://www.msnbc.com/local/wcmh/A1871765.asp
andy — you bring up an interesting question. Where “grounding” and “ground” may be poorly defined terms that do not apply in all cases, “bonding” and “limiting potential difference” might be more accurate. Adjacent conductive objects accessible to unqualified persons should be electrically “jumpered” if their construction or assembly does not permit integral, continuous contact to limit voltage between exposed surfaces.
[This message has been edited by Bjarney (edited 12-11-2003).]
we have all lamp posts grounded with a steel stripe or stuff like that, but shouldnt it be enough without as the post goes far into ground?
The existence of a ground rod or some other connection to earth does not provide any real increase in safety for the installation. The only way to make the installation safe is with the use of an equipment grounding conductor that is run with the power conductors and that is of a low enough impedance to cause the OCPD to open the circuit in the event of a fault. Don