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Author Topic: Teen Saves Brother From Electrocution  (Read 5901 times)

Jonathan Johnson

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Re: Teen Saves Brother From Electrocution
« Reply #10 on: August 04, 2015, 12:19:42 pm »

Martin says that pole was filled with 220 V of electricity...

If it was half full, would it only be 110V?

The real headline should be Teen Escapes Electrocution While Saving Brother. Most instances of attempted rescues from an electrical fault by untrained personnel result in multiple electrocutions.
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Mike Sokol

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Re: Teen Saves Brother From Electrocution
« Reply #11 on: August 04, 2015, 01:10:21 pm »

If it was half full, would it only be 110V?

The real headline should be Teen Escapes Electrocution While Saving Brother. Most instances of attempted rescues from an electrical fault by untrained personnel result in multiple electrocutions.

Yup... Here is one of the saddest incidents I've read about recently. See below:

By NBC News staff

An assistant track and field coach for Idaho State University who tried to save the family dog from an irrigation ditch and two men who went into the canal in an attempt to rescue her were electrocuted, officials said Friday.

Bingham County officials found the bodies Thursday evening about three miles northwest of Blackfoot in southeastern Idaho, according to NBC station KPVI of Pocatello.

Jacquelyn R. Paulson, 31, of Blackfoot, was reported missing about 9:30 p.m. after she failed to return from a search for the family dog, Bingham County Sheriff's Capt. Mark Crowley said. Paulson had been missing for about three hours, according to KPVI.

A group of neighbors and family members went looking for Paulson, and police sent out a reverse 911 call to surrounding residents alerting them about the missing person's report, KPVI reported. The search party expanded to include six deputies and 15 members from a search and rescue team, according to a sheriff's press release.

The search was called off around 10:50 p.m. when the bodies of three victims along with the dog were discovered in an irrigation ditch about 50 yards from the residence, KPVI reported.

Two Blackfoot residents, Michael Lance Hicks, 41, and Preston Keith Tarpley, 49, also died after apparently going into the water in an attempt to rescue Paulson, according to KPVI.

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An irrigation pump in the area had shorted out and was sending an electrical current through the water, deputies said. Idaho Power, a unit of IdaCorp Inc., shut off the power in the area so rescuers could recover the bodies, according to KPVI.

Paulson was going into her ninth season an assistant track and field coach at Idaho State. She was a two-time NCAA All-American in the heptathlon as a student at ISU and competed in the event in the Olympic Trials in 2004 and 2008, finishing eighth in 2008, according to the Idaho State Journal in Pocatello. She also competed internationally, according to news reports.

"She was the pride of our program," ISU head track and field coach Dave Nielsen said in a statement. "She was like a daughter to me. This is so untimely and tragic that I just don't know what else to say."
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Tim Gurske

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Re: Teen Saves Brother From Electrocution
« Reply #12 on: August 22, 2015, 02:50:43 pm »

That is very sad. But, I guess I do not understand how a shorted out pump would make an entire canal "hot." Wouldn't the power already be going through the water to ground?
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Mike Sokol

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Re: Teen Saves Brother From Electrocution
« Reply #13 on: August 22, 2015, 04:59:47 pm »

That is very sad. But, I guess I do not understand how a shorted out pump would make an entire canal "hot." Wouldn't the power already be going through the water to ground?

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Thanks....

Mike Sokol
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Jared Koopman

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Re: Teen Saves Brother From Electrocution
« Reply #14 on: August 22, 2015, 08:49:21 pm »


That is very sad. But, I guess I do not understand how a shorted out pump would make an entire canal "hot." Wouldn't the power already be going through the water to ]

I'm curious the answer to this as well.

Jared
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Mike Sokol

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Re: Teen Saves Brother From Electrocution
« Reply #15 on: August 22, 2015, 08:57:08 pm »

That is very sad. But, I guess I do not understand how a shorted out pump would make an entire canal "hot." Wouldn't the power already be going through the water to ground?

Here's what happens in freshwater with a submerged electrical source. Since normal water has a relatively high resistance, the fault current isn't immediately shorted to earth-ground via the water. Instead, it reaches out into a big hemisphere of voltage gradients that can reach 100 ft. If you get into the middle of this voltage gradient, then one side of your body will have a different voltage than the other side. And that differential voltage will increase as you reach your hands further apart or you get closer to the voltage source. So if you have a 5 ft hand-to-hand reach and there's even 2 volts per foot differential, now you'll have a 10 volt differential between your hands. Since you're wet, you'll have somewhere around 1,000 ohms internal resistance hand-to-hand. A little calculating with ohms law shows that you can have 10 mA of current flowing through you with just a 10 volt differential.

Now we know from experiments that somewhere between 15 and 20 mA of 60 Hz current across your body will cause paralysis of your muscles. So as you feel the shock in the water and try to swim to shore and the source of the voltage (say, a boat dock), this gradient voltage will increase, and so will the current through your body until you're paralyzed. And if you're paralyzed you can't swim and will drown. These are called Electric Shock Drowning (ESD) events since you're not actually electrocuted, you really just drown. Nobody knows how often this happens since an autopsy probably won't show any sings of electrocution. Unless someone hears the victim calling for help and sees that they're getting shocked, it's usually assumed the swimmer got tired in the water and drowned. See http://www.electricshockdrowning.org

The same sort of thing happens with something like a water pump in a ditch with a seal failure allowing water to contact an electrical component. Without a GFCI protecting it, this current fault may only be 1 or 2 amperes (I've personally measured this), not enough to trip a circuit breaker, and causing a voltage gradient reaching out dozens of yards. So now if you contact the water in two different places a few feet apart, such as when you're standing in the water-filled ditch and reach out to help someone who's already been shocked, you yourself can have enough current flowing through you to cause paralysis and perhaps even reach the 30 to 40 mA threshold of Ventricular Fibrillation. That's got to be a bad way to go since you're conscious while unable to save yourself, perhaps for many minutes. But dead is dead, so unless someone comes along quickly who can get you out of the water without getting themselves shocked, and then begins CPR, you'll likely die in minutes.

Saltwater generally doesn't have this extended voltage gradient bubble since it's so conductive that the water shunts any current to earth ground immediately, sometimes enough to trip a 20 amp circuit breaker.

That's how freshwater shocks work, and why GFCIs are so important for anything near the water.
« Last Edit: August 22, 2015, 09:17:03 pm by Mike Sokol »
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Mac Kerr

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Re: Teen Saves Brother From Electrocution
« Reply #16 on: September 02, 2015, 01:30:14 pm »

This popped up on my Facebook feed today:

https://www.facebook.com/167553043271191/videos/1176443179048834/

Mac
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Jonathan Johnson

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Re: Teen Saves Brother From Electrocution
« Reply #17 on: September 02, 2015, 04:07:11 pm »

This popped up on my Facebook feed today:

https://www.facebook.com/167553043271191/videos/1176443179048834/

Mac

The video has great information, but the automatically generated subtitles are... shockingly bad.

Here's another video:

https://www.youtube.com/watch?v=sBUvYh93pQc

(EDIT: I first watched the video Mac posted with the sound off. So if I wasn't making sense, that's why.)
« Last Edit: September 02, 2015, 04:14:31 pm by Jonathan Johnson »
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Jonathan Johnson

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Re: Teen Saves Brother From Electrocution
« Reply #18 on: September 02, 2015, 04:27:32 pm »

A well-produced set of videos about electrical safety out of Canada:

https://www.youtube.com/playlist?list=PL3952A9644407575E

One thing that I don't think the videos mentioned (I haven't watched them all yet) is that if you damage an underground cable, the ground around the dig site can still remain energized even if the machinery is moved away.
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Mac Kerr

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Re: Teen Saves Brother From Electrocution
« Reply #19 on: September 02, 2015, 06:00:27 pm »

The video has great information, but the automatically generated subtitles are... shockingly bad.

Here's another video:

https://www.youtube.com/watch?v=sBUvYh93pQc

(EDIT: I first watched the video Mac posted with the sound off. So if I wasn't making sense, that's why.)

Those subtitles were clearly automatically generated with a speech to text converter and were never edited. You're right, shockingly bad.

Mac
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Re: Teen Saves Brother From Electrocution
« Reply #19 on: September 02, 2015, 06:00:27 pm »


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