# Looping wires for lightning????



## Dennis Alwon (May 9, 2009)

Got a job to move the service in the picture below-- no big deal. The meter has a cabinet sitting on the deck that the ho built and there is a 6 circuit panel next to it. The question I have is the AT&T box that was recently installed in an ugly spot. The installers told the homeowner that there needs to be the loop of wire outside the box because lightning will not travel in a circle.????? Can anyone give credence to this claim cause I have never heard that before. The second picture is a close up of the AT&T panel involved.


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## backstay (Feb 3, 2011)

....


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## guest (Feb 21, 2009)

Oh, the lightning surge will still get through, but there are some who claim that lightning impulses are high frequency and thus coiling the wire like that will act like a choke. ( I say maybe, but most likely not.)

That is also the reason that lightning protection system conductors are supposed to be routed as straight as possible.


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## Frasbee (Apr 7, 2008)

On cell sites we were required to make _very_ gradual bends (ugly) on our grounds because we were told that lightning could burst through a "hard corner". :blink:

Somebody is spreading this information. I'd have to see it to believe it.


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## Big John (May 23, 2010)

Frasbee said:


> On cell sites we were required to make _very_ gradual bends (ugly) on our grounds because we were told that lightning could burst through a "hard corner".


 I know there's a least a half truth to that: Something about a sharp edge tends to focus the electric field. With a high enough voltage impulse it could cause the insulation to fail prematurely at that spot.

-John


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## TOOL_5150 (Aug 27, 2007)

I dont buy that - if it got hit by lightening, it would probably be destroyed, loop or no loop.


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## cultch (Aug 2, 2011)

It's probably one of those things where one way is 'slightly' better than the other way so they do it the slightly better way. 

So that it's not fool proof but it 'may' help in the case of a strike. I think I'd rather it go thru and damaage the equipment then come busrting thru that loop tho...


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## Frasbee (Apr 7, 2008)

Big John said:


> I know there's a least a half truth to that: Something about a sharp edge tends to focus the electric field. With a high enough voltage impulse it could cause the insulation to fail prematurely at that spot.
> 
> -John


When an older journeyman that was (unaware of the spec). saw me running a short wire diagonal to the ground bar he almost flipped his lid.

This sounds like a case for mythbusters!


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## LARMGUY (Aug 22, 2010)

Horse puckey.

Why not tie it in a knot then?

Those demarcs are usually outside and require drip loops. I'll bet they were funning the kid when they trained him and never tod him the true reason.


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## Jlarson (Jun 28, 2009)

mxslick said:


> Oh, the lightning surge will still get through, but there are some who claim that lightning impulses are high frequency and thus coiling the wire like that will act like a choke. ( I say maybe, but most likely not.)
> 
> That is also the reason that lightning protection system conductors are supposed to be routed as straight as possible.


I know a few people that swear by the choke thing. They have no other real surge or LPS at all. I just tell them the big mother of all strikes is out there and it will get them eventually. :laughing:


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## drsparky (Nov 13, 2008)

The bible on grounding to minimize lightning is Motorola R56 standard. It is the world standard and most cell towers and radio stations use it.
Yes you need to make easy bends and all the connections must flow to the ground rods. High energy in any form does not like to take corners.


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## kaboler (Dec 1, 2010)

I once had to drive an hour on crazy rush-hour roads for a safety meeting I didn't need. The chance of me getting killed on my way to the meeting was greater than chance of dying on that jobsite.

So what about the guy who is opening the aluminum doorway as lightning hits?

Ideas like the loops on those wires are a clear-cut example of office people who have nothing to do all day but think of dumb stuff.


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## Wireman191 (Aug 28, 2011)

Doing lightning rods on a data center our wire had to be smooth wide 90's, the theory was the lightning will jump out of the wire if the bend was too tight. It was more of a Chinese finger trap looking wire to. What you have pictured is a bit different then that.


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## Wireman191 (Aug 28, 2011)

kaboler said:


> I once had to drive an hour on crazy rush-hour roads for a safety meeting I didn't need. The chance of me getting killed on my way to the meeting was greater than chance of dying on that jobsite.
> 
> So what about the guy who is opening the aluminum doorway as lightning hits?
> 
> Ideas like the loops on those wires are a clear-cut example of office people who have nothing to do all day but think of dumb stuff.


 Ya, they just do it for the hell of it don't they! Retards!:no:


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## Wireman191 (Aug 28, 2011)

I see it on my satellite TV cables also, and Internet coming into my house. I always thought it was for alittle extra. "just in case"


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## Netree (Sep 3, 2011)

They look like drip loops, to me.


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## Mr. Sparkle (Jan 27, 2009)

I remember somebody telling me the same thing once, I can't remember who so it must have not been that important to me.

And who puts that stuff right next to a door like that?

Or, who puts a door right next to that stuff like that?

And they must be obsessed with cleaning the meter.


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## macmikeman (Jan 23, 2007)

The idea probably got started by a specifying engineer. Dennis, remember all the insane ground rod specifications that used to come out regarding main frame computers back in the day? So if you can remember all that nonsense, usually you can spot the trend whenever it starts showing up again.


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## jwjrw (Jan 14, 2010)

When you install LP systems they say not to install the conductor with sharp bends because the lightning will not follow a sharp bend.....or it will jump off the conductor....:blink:


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## Netree (Sep 3, 2011)

True at high voltage; sharp bends are emission points. Funny things happen at radio frequencies, as well.


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## AVARCHITECH (Sep 2, 2011)

drip-loop


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## Jim Port (Oct 1, 2007)

Mike Holt talks about lightning in this article.

http://ecmweb.com/nec/code_qa/stumped-by-the-code-20110801/


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## hbiss (Mar 1, 2008)

Those are service loops. Probably didn't want to get into an argument with the HO over how it looked so they said it's for lightning to shut him up. 

None of that stuff belongs there including the service. Hope you are moving it outta there. It's a shame that the telephone company just throws their stuff there because the service is there and makes a bad situation worse.

-Hal


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## Dennis Alwon (May 9, 2009)

hbiss said:


> None of that stuff belongs there including the service. Hope you are moving it outta there. It's a shame that the telephone company just throws their stuff there because the service is there and makes a bad situation worse.
> 
> -Hal


That is exactly why they called me to move it. The deck was added twenty years ago and the meter and panel stayed. The part you don't see is that is a doorway there and the door barely misses the panel when it opens. I think that side of the house was an addition.. They should have moved the service back then. Now it is going to cost $2500 on my end alone.


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## Fiftyeggs (Sep 16, 2011)

I chalk it up to insurance and serviceability. If it goes straight in there is no room for error. The structure guys I've seen stuff all the slack they can in the wall. Here it's just pretty. And let's admit it homeowners can be picky so I'd guess he was just blowing him off with the old standard it's a safety thing. Wouldn't lightning eviscerate that small of a gauge wire. Maybe if you had 1,000 of them you might be able to channel it through the grounding system, make it go in a loop or dance a jig. Myth busters help us.


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## Big John (May 23, 2010)

I couldn't find a "frequency" for lightning. If you knew that and the voltage, it'd be pretty easy to figure out how effective those loops would be. They provide a little impedance which is better than nothing, but I don't think it's worth installing.

-John


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## drsparky (Nov 13, 2008)

Big John said:


> I couldn't find a "frequency" for lightning. If you knew that and the voltage, it'd be pretty easy to figure out how effective those loops would be. They provide a little impedance which is better than nothing, but I don't think it's worth installing.
> 
> -John


Lightning is DC, so no frequency.


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## Big John (May 23, 2010)

drsparky said:


> Lightning is DC, so no frequency.


I know, but isn't the theory that the DC pulse has such a huge rise-time that chokes will impede it just as much as a frequency of the same period? 

Isn't that the whole idea behind having to bond both ends of the pipe when you run a GEC through it?

-John


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## Dennis Alwon (May 9, 2009)

drsparky said:


> Lightning is DC, so no frequency.


I heard somewhere that lightning is both ac and dc


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## steelersman (Mar 15, 2009)

Netree said:


> They look like drip loops, to me.


You don't need a drip loop if the wires are coming into the bottom of an enclosure...........duh!!!!!


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