Outage causes shock to mechanic.

[casmurbax]

Outage causes shock to Glenmont Walmart employee

GLENMONT — A Walmart employee in Glenmont suffered an electrical shock and burns Saturday after the power went out while he was working on a car in the auto services department, fire officials said.

The outage occurred about 1 p.m. Saturday while the employee was in the mechanic's pit.

The outage sent a shock through the man, causing minor burns to his left hand.

He was taken to Albany Medical Center, where he reported feeling chest pain, said Marc Futia, an assistant chief with the Elsmere Fire Department. His current condition is unknown.

The outage affected power and traffic lights along Route 9W, and caused "substantial" traffic delays for several hours, Futia said. Power has since been restored to all but the Walmart building, he said Saturday evening.
Selkirk Fire and Bethlehem police also responded to the scene.

http://www.timesunion.com/7day-brea...e-causes-shock-burns-to-Glenmont-11126799.php

I along with the person that left the following comment, would like to know.

"Anybody wanna explain how a power outage can cause an electrical shock to someone working on a car?"

 

[BFBOB]

Electrickery is ... tricky.
For instance, in conventional ignition systems, the spark jumps at the spark plug when the breaker points OPEN, turning power to the coil OFF.


It's possible; a "spark" could be generated at the instant the power was cut.
Perhaps a real electrician will give a better explanation.

 

[LXCam]

im calling ********. Home boy panicked and grabbed the muffler when the power went out.

 

[matt_i]

I think there's another serious problem in the power distribution of the store. The guy was unlucky enough to be in the path of least resistance when the electrical load went way up under some fault condition (enough to trip out the local grid) and it didn't go to the ground path where it should have.

It is pure speculation not knowing more, but seeing as the store is still without power there's probably an investigation underway.

 

[6PTsocket]

Outage causes shock to Glenmont Walmart employee

GLENMONT — A Walmart employee in Glenmont suffered an electrical shock and burns Saturday after the power went out while he was working on a car in the auto services department, fire officials said.

The outage occurred about 1 p.m. Saturday while the employee was in the mechanic's pit.

The outage sent a shock through the man, causing minor burns to his left hand.

He was taken to Albany Medical Center, where he reported feeling chest pain, said Marc Futia, an assistant chief with the Elsmere Fire Department. His current condition is unknown.

The outage affected power and traffic lights along Route 9W, and caused "substantial" traffic delays for several hours, Futia said. Power has since been restored to all but the Walmart building, he said Saturday evening.
Selkirk Fire and Bethlehem police also responded to the scene.

http://www.timesunion.com/7day-brea...e-causes-shock-burns-to-Glenmont-11126799.php

I along with the person that left the following comment, would like to know.

"Anybody wanna explain how a power outage can cause an electrical shock to someone working on a car?"

The **** reporter probably screwed up the facts. He he could have been installing a battery and shorted it with wrench or screwdriver and got a really nasty burn. Shock no way.

Sent from my SM-G900V using Tapatalk

 

[Richard Cranium]

I don't know what a mechanic could do to knock out the power to the entire grid, much less the entire store.

 

[wjamyers]

The **** reporter probably screwed up the facts. He he could have been installing a battery and shorted it with wrench or screwdriver and got a really nasty burn. Shock no way.

Sent from my SM-G900V using Tapatalk

Correct!

Briefly stated, the Gell-Mann Amnesia effect works as follows. You open the newspaper to an article on some subject you know well. In Murray’s case, physics. In mine, show business. You read the article and see the journalist has absolutely no understanding of either the facts or the issues. Often, the article is so wrong it actually presents the story backward-reversing cause and effect. I call these the “wet streets cause rain” stories. Paper’s full of them.

In any case, you read with exasperation or amusement the multiple errors in a story-and then turn the page to national or international affairs, and read with renewed interest as if the rest of the newspaper was somehow more accurate about far-off Palestine than it was about the story you just read. You turn the page, and forget what you know.

 

[SuperCat]

Suspicious circumstances. Could be space aliens.

 

[redmondjp]

Wow! You all don't understand electricity very much! It is definitely possible that the man was shocked as a result of the power outage.

It's something called ground current. Under normal conditions, there shouldn't be any. But under certain circumstances, for example, if a high-voltage line drops onto the ground, that can cause a current to flow through the ground. Or if a three-phase circuit loses one phase, the resulting unbalance on the three-phase circuit can also cause a ground current to flow.

The ground has a lot of resistance in it, so there is a voltage drop across it if there is a high voltage inducing a ground current. Anything in the ground or touching the ground in two or more places that conducts better than the ground itself will then have a current flowing through it. Concrete conducts electricity well, so it is very possible that a person working in the mechanics pit could have been shocked if there was ground current in the area.

Hope this helps connect the dots. You can read all about similar events on the internet.

 

[MBfreak]

redmonjp
Thanks for the input.
Absolutely correct.

Ground fault currents are usually limited to low values /duration by the relay protection. If not properly designed/installed/maintained dangerous conditions may occur.

A side note is that 4-legged animals are much more sensitive since the ground fault current often passes thru the torso, causing instant heart damage.


Ola

 

[rlitman]

Wow! You all don't understand electricity very much! It is definitely possible that the man was shocked as a result of the power outage.

It's something called ground current. Under normal conditions, there shouldn't be any. But under certain circumstances, for example, if a high-voltage line drops onto the ground, that can cause a current to flow through the ground. Or if a three-phase circuit loses one phase, the resulting unbalance on the three-phase circuit can also cause a ground current to flow.

The ground has a lot of resistance in it, so there is a voltage drop across it if there is a high voltage inducing a ground current. Anything in the ground or touching the ground in two or more places that conducts better than the ground itself will then have a current flowing through it. Concrete conducts electricity well, so it is very possible that a person working in the mechanics pit could have been shocked if there was ground current in the area.

Hope this helps connect the dots. You can read all about similar events on the internet.

100% agreed. Such a ground current does not travel that far, however the quoted article states:
"Power has since been restored to all but the Walmart building..."

That pretty much implies that while the outage affected a wide area, its source was a fault in the line supplying the Walmart, and that the fault was in a medium voltage circuit (not the low voltage distribution that you get to your home). A store like a Walmart uses a lot of power, and a medium voltage buried feeder (depending on the grid, perhaps something like 11kV, but it could be much more) could easily be the source of a shock like this.

 

[mizzoutrover]

Look up "Step Potential", here is a link, http://www.esgroundingsolutions.com/what-is-step-and-touch-potential/

Sounds like the transformer serving the Walmart faulted to ground, my guess is the transformer is adjacent to the auto shop. The fact the individual was working on a car was coincidental. The mention that Walmarts power was not restored supports this guess...

Electrical substation designers must consider step potential all the time.

 

[joe_padavano]

I don't know what a mechanic could do to knock out the power to the entire grid, much less the entire store.

Might want to brush up on your reading comprehension. Nowhere does it say that the mechanic CAUSED the outage, only that he was shocked AFTER the outage.