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Anonymous Poster #1

Electrical Attraction Force for AC Supply

12/23/2015 5:25 AM

There's what you call electrostatic force in DC which is straight forward Coulomb's Law.

How can you explain the attraction force in AC supply?

Like this guy is stuck in AC distribution panel.

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#1

Re: Electrical Attraction Force for AC Supply

12/23/2015 7:08 AM

This is why amateurs should not work on power distribution.

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#2

Re: Electrical Attraction Force for AC Supply

12/23/2015 8:38 AM

It looks to me like the attraction force was ignorance. That accounts for the fact that he was bonded to the supply conductors in much the same way that my wife sometimes burns the hell out of something on the stove and then has a hard time cleaning the pan.

I would have to call that cooked to death, literally.

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#3

Re: Electrical Attraction Force for AC Supply

12/23/2015 9:18 AM

All the more reason to BAN ANONYMOUS POSTS AND ANONYMOUS POSTERS, like you.

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#4

Re: Electrical Attraction Force for AC Supply

12/23/2015 9:44 AM

Static electricity with voltage of many thousands of volts can attract very light objects such a dust or bits of paper, but the electrical forces from voltages used for electrical distribution are far too weak to attract even light objects, much less an object with the mass of a human being.

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#5
In reply to #4

Re: Electrical Attraction Force for AC Supply

12/23/2015 10:12 AM

but how come the guy was stuck? He only fell when the wire was cut. Can you figger out that one?

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#6
In reply to #5

Re: Electrical Attraction Force for AC Supply

12/23/2015 11:04 AM

Nothing to figure out, contact with live wires causes contraction of the muscles that prevent the release of the hand from the conductor. You play you die.

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#9
In reply to #6

Re: Electrical Attraction Force for AC Supply

12/23/2015 2:49 PM

Exactly. You may not be attracted, but once there, you can't let go.

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#7
In reply to #5

Re: Electrical Attraction Force for AC Supply

12/23/2015 11:24 AM

It's the oscillating current that gets ya....

http://blog.cheaperthandirt.com/stun-guns-and-how-they-work/

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#8
In reply to #5

Re: Electrical Attraction Force for AC Supply

12/23/2015 1:31 PM

Coulomb attraction still applies.

The current changes direction every 60th of a second (or 50th of a sec, depending on how the generator is set up), but that's an extremely long time compared to the speed of the electrical force. The attractive force doesn't suddenly become a repulsive force just because the current changed directions. It's an attractive force no matter which way the current is going.

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#12
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Re: Electrical Attraction Force for AC Supply

12/24/2015 12:23 PM

It seems The back part of his body, perhaps got charred during the electrical arcing.... That burned part that served as the shorting element will be similar to a situation where the meat that is being cooked get stucked to the grill when one is grilling or cooking barbecue!

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#10

Re: Electrical Attraction Force for AC Supply

12/23/2015 7:11 PM

That had nothing whatsoever to do with Coulomb's Law...

There was some sort of accident, precipitated by a foolish undertaking by someone not qualified to be doing whatever it was he did. He died in that accident, and ended up suspended by the neck on something that we cannot see, either as an act of suicide or the result of having been shocked. The massive burns indicate a shock, but we can't determine from that video what happened first or last or why.

My guess is that he was on top of that cabinet trying to do something with the big transformer behind it, was electrocuted in the process, and in the jerking around of that electrocution, ended up getting his head and neck in between some cables which either hanged him, or just suspended his corpse after he was dead from the electrocution. In retrieving the corpse, they elected to cut the cable after giving up trying to manipulate it.

However, nothing involved in that had anything to do with electrostatic forces.

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#11
In reply to #10

Re: Electrical Attraction Force for AC Supply

12/23/2015 8:44 PM

It sad to say, we have to watch the safety of our team. Now they are actively alive, suddenly they are taken away. It happens so fast like these guys from China transferring scuff hold. I don't know if its laziness or lack of safety training that took these guys life.

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#13

Re: Electrical Attraction Force for AC Supply

12/24/2015 12:39 PM

The force between current carrying conductors is not found from Coulomb's law, which gives the force between charges. There is no net charge in a current carrying conductor. The force is given by the Biot-Savart law, but it's quite small. I make it 0.1N/m between 2 parallel conductors 10mm apart, each carrying 10 amps (DC).

But nothing to do with your guy in the panel.

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#14

Re: Electrical Attraction Force for AC Supply

12/24/2015 4:36 PM
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#15

Re: Electrical Attraction Force for AC Supply

12/25/2015 3:59 PM

I haven't looked at the video, but the effects of DC is to cause muscles to shorten, this often has the effect of removing the finger or arm totally involuntarily.

AC locks the muscles in a position (already touching AC!) and prevents further movement. Its a killer.

The RN had up to the end of the 1940s, all DC ships with open switchboards.

With NATO came a standard power system for NATO Navy vessels of AC 440 Volts 3 phase, no neutral, at 60Hz..

The first RN ship built to the new standard was a Daring class destroyer, with open face switchboards. There were so many serious accidents, that had never occurred on the DC ships, that the ship was refitted with closed face switchboards.

Since then, only closed face switchboards have been used.

I worked on a DC Aircraft carrier, 220 volts, open faced switchboards. I have had many DC shocks, uncountable, but the few AC shocks I had on 440 VAC remain etched into my memory!!!!

The Royal Navy Daring Class ships were built in two groups, one with the traditional DC electrical system (Daring, Dainty, Defender and Delight) and the remaining ships (Decoy 1949, Diamond 1950, Diana 1952 and Duchess 1951), with a modern AC system.

I don't know which was the problem ship 100%, but probably Decoy with a launch date of 1949. I can find no online information to support my claims.....probably suppressed....it was part of our training to know of this huge safety difference between AC & DC....

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#16

Re: Electrical Attraction Force for AC Supply

12/26/2015 3:21 AM
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#17
In reply to #16

Re: Electrical Attraction Force for AC Supply

12/26/2015 4:48 AM

Excellent link, many thanks for sharing with us all here.

I wish everyone would take the time to supply links that support their take on a particular subject!!

I particularly liked the (in red in the link) following comment. It supports my experience and knowledge perfectly, BUT FEW TEXTBOOK WRITERS SEEM TO KNOW THIS!!

How AC affects the body depends largely on frequency. Low-frequency (50- to 60-Hz) AC is used in US (60 Hz) and European (50 Hz) households; it can be more dangerous than high-frequency AC and is 3 to 5 times more dangerous than DC of the same voltage and amperage.

Low-frequency AC produces extended muscle contraction (tetany), which may freeze the hand to the current's source, prolonging exposure. DC is most likely to cause a single convulsive contraction, which often forces the victim away from the current's source.

PERFECT!!!!!!

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