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Electricity And Magnetic Micros

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I was about to place a cache today, underneath the huge, lit sign like those of gas stations, drug stores etc., when something bizarre happened. There was an open area between the ground and the metal base of the sign where I could reach in and attach the micro. As I placed the micro, my knee touched the ground and I felt a strong, but not harmful tingling in the fingers holding the micro. I thought that was wierd and touched the bottom edge of the base again, and didn't feel anything. Odd, I thought. Then I realized my knee was off the ground, so I touched the base of the sign with one hand and touched the ground with the other, and felt a strong current of electricity at both fingertips. I know, curiousity killed the cat...

 

Has anyone else ever encountered anything like that before while caching? Is the sign wiring damaged, or is that normal for those big signs?

 

Team Maccabee

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I have been shocked before, but not while caching.

 

Apparently you presented a shorter path to ground for that short in the wiring.

 

You need to tell somebody who can fix it.

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I certainly did not hide it there after that!! I'll find a different location for it. Figuring it was a glitch, I did tell the management what happened when I was "tying my shoes."

 

Team Maccabee

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I certainly did not hide it there after that!! I'll find a different location for it. Figuring it was a glitch, I did tell the management what happened when I was "tying my shoes."

 

Team Maccabee

Glad you only got a little zap and nothing serious :D

 

But the "tying your shoes" makes me wonder... were you going to place a cache on thier sign without telling them?

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Glad you only got a little zap and nothing serious  :D

 

But the "tying your shoes" makes me wonder... were you going to place a cache on thier sign without telling them?

I certainly might and frankly I would have no problem doing it.

Edited by sbell111

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There is an open hot wire on the sign - sounds like there are some wires toughing somewhere inside. Consider letting the MGT know that you touched the sign and got shocked. The sign or whatever is there is unsafe and needs attention.

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I was about to place a cache today, underneath the huge, lit sign like those of gas stations, drug stores etc., when something bizarre happened.  There was an open area between the ground and the metal base of the sign where I could reach in and attach the micro.  As I placed the micro, my knee touched the ground and I felt a strong, but not harmful tingling in the fingers holding the micro.  I thought that was wierd and touched the bottom edge of the base again, and didn't feel anything.  Odd, I thought.  Then I realized my knee was off the ground, so I touched the base of the sign with one hand and touched the ground with the other, and felt a strong current of electricity at both fingertips.  I know, curiousity killed the cat...

 

Has anyone else ever encountered anything like that before while caching?  Is the sign wiring damaged, or is that normal for those big signs?

 

Team Maccabee

The metal base is not grounded as it should be, any bare wire touching the base would have ordinarily caused a fuse to blow or breaker to trip. Either it was never grounded, or someone discovered that removing the ground stopped the breaker from tripping. You provided the path to ground. You only felt it when you were on your knees because when you were standing, your shoes insulated you from the ground. Rubber soles I would imagine. If you really wanted to have a story to tell your grandkids from your hospital bed, you should have licked your fingers first. :D

 

By the way, passing a current from fingertip to fingertip as you did is the wost possible path for electricity to take. You're pretty lucky you can write about it. At this point I would think it is your duty to see this through and let the owner know of the danger before someone gets hurt or killed.

Edited by cachew nut

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... At this point I would think it is your duty to see this through and let the owner know of the danger before someone gets hurt or killed.

Ummm, he already did.

  Figuring it was a glitch, I did tell the management what happened when I was "tying my shoes."

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By the way, passing a current from fingertip to fingertip as you did is the wost possible path for electricity to take. Your pretty lucky you can write about it. At this point I would think it is your duty to see this through and let the owner know of the danger before someone gets hurt or killed.

I agree completely. Although it felt just a little stronger than licking a 9V battery as a kid, I told the management immediately. They said they would get someone out to check it as soon as possible.

 

Team Maccabee

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By the way, passing a current from fingertip to fingertip as you did is the wost possible path for electricity to take. Your pretty lucky you can write about it. At this point I would think it is your duty to see this through and let the owner know of the danger before someone gets hurt or killed.

I agree completely. Although it felt just a little stronger than licking a 9V battery as a kid, I told the management immediately. They said they would get someone out to check it as soon as possible.

 

Team Maccabee

I'm willing to bet that as long as the sign continues to work, no one will do a bloody thing about it.

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By the way, passing a current from fingertip to fingertip as you did is the wost possible path for electricity to take. Your pretty lucky you can write about it. At this point I would think it is your duty to see this through and let the owner know of the danger before someone gets hurt or killed.

I agree completely. Although it felt just a little stronger than licking a 9V battery as a kid, I told the management immediately. They said they would get someone out to check it as soon as possible.

 

Team Maccabee

I'm willing to bet that as long as the sign continues to work, no one will do a bloody thing about it.

I bet you're right. Maybe someone should go back with a copper wire, and touch that to ground :D. That would 'fix' the problem.

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Stupid electricity. It seems like more and more these days, electricity has it in for geocachers everywhere. :D

Electricity is everywhere these days. I see log after log mentioning it. :D

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... At this point I would think it is your duty to see this through and let the owner know of the danger before someone gets hurt or killed.

Ummm, he already did.

Alright then. My job here is done. Carry on!

 

:ph34r:

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A lot of people have a little bit of knowledge about electricity and a little knowledge can be a dangerous thing. It is not uncommon for an electrical device to have a bit of leakage in the insulation. This is not uncommon. Normally there is enough resistance that no dangerous amount of current will flow. Had the sign been connected directly to a hot wire, you would not have felt it... for very long! :ph34r:

 

It was a good idea to not place the cache there. But there is likely no danger from this sign... unless you climb it! ;)

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A lot of people have a little bit of knowledge about electricity and a little knowledge can be a dangerous thing.  It is not uncommon for an electrical device to have a bit of leakage in the insulation.  This is not uncommon.  Normally there is enough resistance that no dangerous amount of current will flow.  Had the sign been connected directly to a hot wire, you would not have felt it... for very long!  :ph34r:

 

It was a good idea to not place the cache there.  But there is likely no danger from this sign... unless you climb it!      ;)

I will have to disagree. I've been a electricial troubleshooter for over a quarter of a centry and can tell you that it is very uncommon for any kind of "leakage" to occur in properly installed undamaged lines. A grounding conductor could be broken, not connected or have a poor connection thus creating a hazardous, above-ground potential which creates a shock hazard. If this cacher had a damp hand reaching in and the other hand grabbed hold of a solid ground then the electric flow would have followed a short path through the heart. A standard circuit for a sign is 20 or 30 amps yet only .1 to .2 amps of current thorough the heart will start ventricular fibrillation (i.e. kill you)! So don't become a part of the electrical circuit. The owners need to have an electrician check out the system, else somebody could really get hurt - no climbing required.

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I will have to disagree.... yet only .1 to .2 amps of current thorough the heart will start ventricular fibrillation ... The owners need to have an electrician check out the system, else somebody could really get hurt...

 

A fellow CBET?

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That's why anytime I'm working around electricity I keep one hand in my pocket! I learned that trick in grad school, where I was working with high voltage.

 

I took 18,700 volts to my right hand at the back of my high voltage power supply. My arm hurt for several weeks.

 

I can also tell you what that sounds like. It sounds like this... CRACK! "Oh s*** s*** s***!"

 

:ph34r::);)

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I got zapped searching a WWII vintage search light for a micro. It's in front of an aviation museum. I reckon I put my hand where it didn't belong. LOL! :blink:

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...But there is likely no danger from this sign... unless you climb it! :blink:

I also must disagree with this (although with out as much authority as the other person...).

 

While its rather unlikely that someone will kill themselves, it certainly is possible. It doesn't take much current to screw up your heart. The circumstances though that would lead to the current running through your heart probably are a wee bit improbable (otherwise someone would be dead already), but they aren't astronomically unlikely (like a few people have said, damp hands will 'help', relative positioning of where the current it going in to where its going out, etc etc.

 

I too keep one hand in my pocket when I'm not 110% sure of the source I'm working around (picked it up in grade 10 Physics class, and was drilled in to me a few times in my Physics degree)...

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I too keep one hand in my pocket when I'm not 110% sure of the source I'm working around (picked it up in grade 10 Physics class, and was drilled in to me a few times in my Physics degree)...

When I have to wonder about a connection, I always lift the opposite foot of the hand I am grabbing with. (Grab with the right, stand on the right) less chance of having the current pass through my heart.

 

Not sure if it works, but what the hey, ya know?

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Team Maccabee

I'm willing to bet that as long as the sign continues to work, no one will do a bloody thing about it.

This is scary, but probably true. There is a bridge closed in Columbus Ohio due to a lamppost shorting out onto the bridge decking. A 10-yr old boy was electrocuted and killed walking across the bridge in the rain. Someone else had reported getting shocked on that bridge sometime earlier. Engineers couldn't figure out what was wrong because they were checking it in good weather. That was over a year ago, I believe.

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As I placed the micro, my knee touched the ground and I felt a strong, but not harmful tingling in the fingers holding the micro. I thought that was wierd and touched the bottom edge of the base again, and didn't feel anything. Odd, I thought. Then I realized my knee was off the ground, so I touched the base of the sign with one hand and touched the ground with the other, and felt a strong current of electricity at both fingertips. I know, curiousity killed the cat...

Sounds like you just got a 110 volt shock. They aren't as bad as you would expect, but you were probably nice and dry. You should be happy it wasn't raining! Electricity tends to travel across your skin, unless you are wet, then it has an easier time penetrating the body. It may have felt like a 9v battery on the tounge, but it was probably the full 110. After all, you've never felt 9v on your finger's have you?

 

It definately sounds like what others have said already, the hot wire is shorted to the metal frame somewhere. With proper wiring, the metal frame should have been grounded, which would have tripped the breaker when the hot touched it. Probably someone found out disconnecting the ground stopped the breaker from tripping, so they did that instead of calling in an electrician. Sad but true. It was good of you to tell the store owner!

 

Happy caching!

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The thing was, it has been raining and the ground was really soaked (but no puddle there). I was lucky, I guess...

 

Team Maccabee

I meant you were lucky it wasn't raining because you and your skin were dry. Had you been actually in the reain at the time, it probably would have been worse.

I assumed that the ground was wet because of the season, and also if the ground was dry you probably wouldn't have felt anything anyway.

 

Stay safe!

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I was about to place a cache today, underneath the huge, lit sign like those of gas stations, drug stores etc., when something bizarre happened. There was an open area between the ground and the metal base of the sign where I could reach in and attach the micro. As I placed the micro, my knee touched the ground and I felt a strong, but not harmful tingling in the fingers holding the micro. I thought that was wierd and touched the bottom edge of the base again, and didn't feel anything. Odd, I thought. Then I realized my knee was off the ground, so I touched the base of the sign with one hand and touched the ground with the other, and felt a strong current of electricity at both fingertips. I know, curiousity killed the cat...

 

Has anyone else ever encountered anything like that before while caching? Is the sign wiring damaged, or is that normal for those big signs?

 

Team Maccabee

This is not uncommon in lamp posts and lighted signposts in the USA, and is even far more common in parts of Central and South America and in places such as India, where electrical technology is often used rather carelessly. The papers in may of these places bear stories every day of shocks and fatalities from lampposts and sign posts.

 

The shock you experienced was real, and was due to two facts: there was a mioor electircal short (perhaps due to water buildup around wires or wire connectors) in the AC electrical wiring supplying the sign, and (most improtantly) the metal parts of the pole and sign were not well-grounded, perhaps because the installing electrician failed to install a ground wire, or perhaps because the ground wire or its connection corroded or came loose. Such shocks can be mild, or they can be severe, or they can be fatal. In fact, a few months ago, our local newspaper reported that a maintenance worker at a nearby community college here in Frederick County, Maryalnd died as a result of such a shock. The college maintenance department had apprently received complaints that a certain lamppost on campus was giving students electrical shocks if they touched it. Apparently (if my memory of the story serves me), the young manintenance man approached the lamp post on a rainy day, with his toolbox in hand, to investigate the possible problem. He touched the lamppost, and with his feet on wet ground, he died immediately from a massive electrical shock.

 

Being an ex-electrical engineer, I tend to notice such reports in the media. And frankly, this knowledge caused me some tense moments when I first started hunting those ubiquitous silly micros hidden under lamp post skirts. So, the few times I go after such things, I always touch the pole first with my right hand, so at least if there is a very serious electrical "leak", the current will at lesat be carried to my feet (or knees) via the right side of my body, and not thru my heart. (The latter precaution is something which every ham radio operator and tinkerer learns at an early age!)

 

I do hope that you did not and do not place a cache in that sign post. It sounds like a serious injury or a fatality waiting to happen! Glad you were not hurt!

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Electrical problems can be hard to troubleshoot sometimes. In this case it sounds like the most probable cause of the shock is that there is a short or at least some current leakage to the metal sign. If there is flourescent lighting in the sign then there is a good chance that one of the ballasts is bad or that one of the leads going to one of the bulb sockets is in contact with metal. (i believe this voltage is higher than 120 or 240 but the amperage is very low)

 

Still, as mentioned above, the biggest problem is that the sign itself is not properly grounded.

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Well, for you cynical folk out there, just wanted to let you know that they had an electrician out this afternoon working on it. Now, I don't know if it was fixed, and am a bit loathe to test it myself....

 

Team Maccabee

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There was a thread or two about this a while ago. Talking about a couple people being killed walking over the covers in sidewalks for electrical stuff....or dogs being killed. Dogs seem to be more affected, maybe because they are smaller or barefoot. A thread was started because someone was killed while sitting in a bus shelter.

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There was a thread or two about this a while ago.  Talking about a couple people being killed walking over the covers in sidewalks for electrical stuff....or dogs being killed.  Dogs seem to be more affected, maybe because they are smaller or barefoot.  A thread was started because someone was killed while sitting in a bus shelter.

Dogs zapped by NYC sidewalk - The Washington Times

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Hmmm electricity and geocaching. I seem to remember a thread about that last week. :unsure:

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A lot of people have a little bit of knowledge about electricity and a little knowledge can be a dangerous thing.

 

But there is likely no danger from this sign... unless you climb it!      :lol:

 

LOL! I guess you include yourself among the ones who know a little bit. :unsure::anibad: In this case the danger was from touching the sign and the ground at the same time. Unless there was a chance of touching another hot conductor or ground (entirely possible), the danger from climbing the sign would be falling off. :P

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Many folks underestimate the danger associated with faulty electrical equipment. You may often hear things such as "its only 120 volts ... it can't hurt you". Wrong, 120 volts can kill you. Any device that gives even a mild electrical shock should be immediately unplugged if possible, and examined by an electrician or repairman ASAP. The shock may be mild only because there is not a good path to ground, and if a better path occurs, due to damp conditions or contact with a grounded object ... bad things happen.

 

Many years ago, an acquaintance was almost killed by her refrigerator. She had received mild shocks from the 'frig before and had ignored the problem. But this time she grabbed the door handle with one hand and the cold water faucet with the other ... the faucet is well grounded. Her muscles contracted from the shock and she was locked into place. She would have died except her son realized what was happening and tackled her to knock her off the circuit.

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A lot of people have a little bit of knowledge about electricity and a little knowledge can be a dangerous thing.

 

But there is likely no danger from this sign... unless you climb it!      :D

 

LOL! I guess you include yourself among the ones who know a little bit. :D:D In this case the danger was from touching the sign and the ground at the same time. Unless there was a chance of touching another hot conductor or ground (entirely possible), the danger from climbing the sign would be falling off. :D

As a trained electrical engineer (old profession; I have since moved on to other fields) and a degreed scientist, I agree with this assessment by Cachew Nut about the possible hazards of climbing the sign pole.

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I was about to place a cache today, underneath the huge, lit sign like those of gas stations, drug stores etc., when something bizarre happened.  There was an open area between the ground and the metal base of the sign where I could reach in and attach the micro.  As I placed the micro, my knee touched the ground and I felt a strong, but not harmful tingling in the fingers holding the micro.  I thought that was wierd and touched the bottom edge of the base again, and didn't feel anything.  Odd, I thought.  Then I realized my knee was off the ground, so I touched the base of the sign with one hand and touched the ground with the other, and felt a strong current of electricity at both fingertips.  I know, curiousity killed the cat...

 

Has anyone else ever encountered anything like that before while caching?  Is the sign wiring damaged, or is that normal for those big signs?

 

Team Maccabee

The metal base is not grounded as it should be, any bare wire touching the base would have ordinarily caused a fuse to blow or breaker to trip. Either it was never grounded, or someone discovered that removing the ground stopped the breaker from tripping. You provided the path to ground. You only felt it when you were on your knees because when you were standing, your shoes insulated you from the ground. Rubber soles I would imagine. If you really wanted to have a story to tell your grandkids from your hospital bed, you should have licked your fingers first. :D

 

By the way, passing a current from fingertip to fingertip as you did is the wost possible path for electricity to take. You're pretty lucky you can write about it. At this point I would think it is your duty to see this through and let the owner know of the danger before someone gets hurt or killed.

Light poles like that aren't on a breaker, unfortunately. That's how they kill. Usually the lug holding the ground to the pole oxidizes, in turn losing diameter and becoming loose. If it is a 277v pole or higher(which usually, anything over 12' tall is)it could just be a wire that's close to the metal inside, not just touching it, and it's arcing (which wouldn't deliver the full charge) when he created a weak(but stronger than what it was equipped with) ground, completing the circuit. I recommend definately telling the store manager. You were a very lucky fella, a kid was killed near here a year or so ago by touching one with the same problem. Dont underestimate the power in anything outside, it's not like the stuff in your house. Take a 4' flourescent tube lightbulb to your closest powerlines(not telephone poles along the street) steel towers with 3 sets of wires. High tension wires. Hold the metal end in your hand, and hold it up over your head. It works better if you're grounded, but in no way can it arc to you, or shock you. Also, do it in the dark. It doesn't light it up like it would in the fixture, but it lights up. Thought of trying to use it in a nocturnal, but.......

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A lot of people have a little bit of knowledge about electricity and a little knowledge can be a dangerous thing.

 

But there is likely no danger from this sign... unless you climb it!      :D

 

LOL! I guess you include yourself among the ones who know a little bit. :D:( In this case the danger was from touching the sign and the ground at the same time. Unless there was a chance of touching another hot conductor or ground (entirely possible), the danger from climbing the sign would be falling off. ;)

As a trained electrical engineer (old profession; I have since moved on to other fields) and a degreed scientist, I agree with this assessment by Cachew Nut about the possible hazards of climbing the sign pole.

You see birds sitting on high voltage lines everyday. They are prefectly fine unless they happen to touch ground or another high voltage line while they're doing it! :(

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I was about to place a cache today, underneath the huge, lit sign like those of gas stations, drug stores etc., when something bizarre happened.  There was an open area between the ground and the metal base of the sign where I could reach in and attach the micro.  As I placed the micro, my knee touched the ground and I felt a strong, but not harmful tingling in the fingers holding the micro.  I thought that was wierd and touched the bottom edge of the base again, and didn't feel anything.  Odd, I thought.  Then I realized my knee was off the ground, so I touched the base of the sign with one hand and touched the ground with the other, and felt a strong current of electricity at both fingertips.  I know, curiousity killed the cat...

 

Has anyone else ever encountered anything like that before while caching?  Is the sign wiring damaged, or is that normal for those big signs?

 

Team Maccabee

The metal base is not grounded as it should be, any bare wire touching the base would have ordinarily caused a fuse to blow or breaker to trip. Either it was never grounded, or someone discovered that removing the ground stopped the breaker from tripping. You provided the path to ground. You only felt it when you were on your knees because when you were standing, your shoes insulated you from the ground. Rubber soles I would imagine. If you really wanted to have a story to tell your grandkids from your hospital bed, you should have licked your fingers first. :D

 

By the way, passing a current from fingertip to fingertip as you did is the wost possible path for electricity to take. You're pretty lucky you can write about it. At this point I would think it is your duty to see this through and let the owner know of the danger before someone gets hurt or killed.

Light poles like that aren't on a breaker, unfortunately. That's how they kill. Usually the lug holding the ground to the pole oxidizes, in turn losing diameter and becoming loose. If it is a 277v pole or higher(which usually, anything over 12' tall is)it could just be a wire that's close to the metal inside, not just touching it, and it's arcing (which wouldn't deliver the full charge) when he created a weak(but stronger than what it was equipped with) ground, completing the circuit. I recommend definately telling the store manager. You were a very lucky fella, a kid was killed near here a year or so ago by touching one with the same problem. Dont underestimate the power in anything outside, it's not like the stuff in your house. Take a 4' flourescent tube lightbulb to your closest powerlines(not telephone poles along the street) steel towers with 3 sets of wires. High tension wires. Hold the metal end in your hand, and hold it up over your head. It works better if you're grounded, but in no way can it arc to you, or shock you. Also, do it in the dark. It doesn't light it up like it would in the fixture, but it lights up. Thought of trying to use it in a nocturnal, but.......

The OP was posting about an outdoor sign and not an outdoor light pole. UL 48 spells out requirements of electric signs, although the sign manufacturer does not necessarily have to have his signs UL (Underwriter Labs) approved. It's a good idea though, if he wants to sell signs and have the inspector ok the installation quickly.

 

The NEC (National Electrical Code) Article 600 describes bringing the wiring to the sign, and grounding, among other things. This most likely happened correctly and was checked by an inspector. The code specifies that the sign shall be controlled by an externally operable switch or circuit breaker. That would be located on the outside of the sign. If a switch is used outside, than the breaker will be located in the building. You need to have the circuit on a breaker or fuse otherwise you stand the chance of melting the wires.

 

I've seen the loose lug scenario before, that's as good a guess as any.

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There have been many cases of this, here are just a few... The reason dogs are susceptable is indeed because they are "barefoot" (barepaw?)

 

Dog Electrocuted On Charlestown Sidewalk

"Another dog has been killed by stray voltage on a Boston sidewalk."

 

More Dogs Electrocuted in New York

 

City Utility Boxes are a Powerful Danger (Maryland)

 

Could police have saved electrocuted woman’s life? (junction box cover, New York)

 

Sidewalk Shocks Kill Walker, Dogs (Woman and two dogs killed, New York)

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