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[Mike Sokol]

Just saw this story on EC&M this morning. The takeaway is that all conduits need to be properly grounded.

Mike

A 16-year-old was nearly electrocuted during a game of hide and seek in the Tampa, Florida, area last week when his younger brother pulled him from the current.

According to a report from ABC Action News, the two brothers say they were playing manhunt, a game much like hide and seek. In an attempt to get to the roof to hide, 16-year-old Justin Martin says he jumped onto an air conditioning unit and grabbed a metal pole hoping to climb up to the roof.

Martin says that pole was filled with 220 V of electricity, and he thought he was paralyzed by the shock. Unable to move, he screamed for help.

His 13-year-old brother Dominic tried to pull his brother off the pole by grabbing his clothes but he said the electrical current was too strong.  Not knowing what to do next, Dominic said he decided to tackle him, and they both fell back, breaking the hold.

Their mom, Grace Martin, said she talked to property managers about the pipe and was told it wasn't grounded properly, according to the news report. She was told that may be the reason why it shocked her son.  Property managers have since covered that metal pole with PVC.

Withlacoochee River Electric Cooperative did a site survey of the area and said the equipment that shocked the teen didn't belong to the power company. Pasco County code enforcement would be responsible for checking it, the report said.

[Tim McCulloch]

So they put a band-aid on it (PVC condom) rather than immediately taking a life-threatening piece out of service.  I hope Pasco County shuts them down and the mom sues them.

[Mike Sokol]

So they put a band-aid on it (PVC condom) rather than immediately taking a life-threatening piece out of service.  I hope Pasco County shuts them down and the mom sues them.

Yeah, you noticed that, eh? Seemed a little wacky to me as well.

[John Roberts {JR}]

I'm glad the kid was able to save his brother... many less clever would get stuck too...

JR

[Scott Wagner]

It seems to me that it would've been far easier to simply ground the conduit than to fit PVC over the entire run.

[Stephen Kirby]

Glad that nobody was permanently hurt.  But the story is odd.  I recognize that "filled with 220V of electricity" is a layman's terminology.  But do they mean that it had 220 running inside it, or the conduit itself was hot at 220 WRT ground?  How does that happen?  One leg miswired hot to ground would put 110 on it.  Not sure how a semi isolated conduit can float up that high.  I'd like to understand this, another thing to watch out for/test for in unknown venues if it's possible.

[Mark Cadwallader]

It seems to me that it would've been far easier to simply ground the conduit than to fit PVC over the entire run.

No, because that would have required fixing all the related items that are out of spec. (End snark.)

[Stephen Swaffer]

Glad that nobody was permanently hurt.  But the story is odd.  I recognize that "filled with 220V of electricity" is a layman's terminology.  But do they mean that it had 220 running inside it, or the conduit itself was hot at 220 WRT ground?  How does that happen?  One leg miswired hot to ground would put 110 on it.  Not sure how a semi isolated conduit can float up that high.  I'd like to understand this, another thing to watch out for/test for in unknown venues if it's possible.

Again, layman's terminology, as in "big wires, big numbers, big hurt, much money to pay".  I am always amazed at how many people are afraid of "220". but think nothing of 120.  A phase to phase shock is rare and a phase to ground shock from 220 is the same as 120-but people don't pay me to wire what they are not afraid of, so there is no incentive to waste the energy to try to educate them beyond their understanding.

Who metered it?  Maybe the AC unit was hot and the pipe (water? gas? structural?) was grounded?  Telling her it was not properly grounded seems to be blame shifting.

[David Buckley]

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

That is a lovely turn of phrase...

[Tim McCulloch]

That is a lovely turn of phrase...

Something Freudian.

[Jonathan Johnson]

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.

[Mike Sokol]

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."

[Tim Gurske]

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?

[Mike Sokol]

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?

Please go to the control panel and change your screen name to your actual name per the terms of this forum.

Thanks....

Mike Sokol

[Jared Koopman]

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

[Mike Sokol]

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.

[Mac Kerr]

This popped up on my Facebook feed today:

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

Mac

[Jonathan Johnson]

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.)

[Jonathan Johnson]

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.

[Mac Kerr]

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

[ProSoundWeb Community]