Looping wire for lightning????

Status
Not open for further replies.
Dennis Alwon

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
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.

ry%3D480
ry%3D480
 
To a certain extent, the loop presents a higher impedance to the pulse of lightning, but since there should be an arrestor anyway, I wouldn't bother. ISTR reading something about doing this in switch yards and on outdoor antenna feeds, but can't recall were.
 
Twoskinsoneman said:
Never heard that but I'm about to go make a loop in all the cords of power surge strips in my house just in case :lol:
Click to expand...
That's what the ho said-- If this were true then the electricians would loop all there wires. I told her I had never heard of it but there could be some truth to it. She said I was being diplomatic. :lol: Me..... I don't think so- If I knew it was BS I would have said it, but I am not about to tell AT&T how to wire their stuff.
 
I think I would put that one in the book along side of the running a cable in a sharp bend zig zag which does have some merit but very little:huh:

Lightning will treat all the conductors in a cable as one conductor, having a loop will not attenuate the voltage, a grounded iron ferrite choke would have much more effect then this plain loop, but even then I wouldn't take it to the bank.
 
Someone peed on the HO's leg & told him it was raining.:D

I'm sure they left the loops in case either box needed moving later on, or to allow plenty of cable if were needed to be reconnected several times down the road, maybe having to cut some off each time.

I see those loops all the time on traffic lights too.
 
Had heard of some comm tower installations where the coax is bonded to the tower as usual near the base, then as the coax comes off the tower to head into the building, a couple of large loops are made. The hope is the extra inductance will direct lightning energy into the tower base and the earth instead of into the building. Don't think it's going to make a big difference on the install in the picture...but i guess it can't hurt, and the service loops might be handy...kinda ugly, though.
 
Those look like drip loops to me. That's probably how the tech was shown to wire them. He didn't want to appear like he didn't know what the loops were for so he came up with that line.:happysad:

I used to work with a guy that I would over hear him "trying" to explain something to an operator that had ask him a question. I would ask him what the heck he was talking about? He would say, I don't know but it sounded good though.
 
Last edited:
99% sure there is another snake oil salesman in town. The lightning jumps through extremely large air gaps but won't go in circles or just jump past the circle HMMMMM.
 
WIMaster said:
99% sure there is another snake oil salesman in town. The lightning jumps through extremely large air gaps but won't go in circles or just jump past the circle HMMMMM.
Click to expand...

There has to be something for the current to jump to, and there isn't in those images.
 
tallgirl said:
There has to be something for the current to jump to, and there isn't in those images.
Click to expand...
But it is there:every thing around the loop at ground potential for the spark of side flash to jump to.
 
jmellc said:
Someone peed on the HO's leg & told him it was raining.:D

I'm sure they left the loops in case either box needed moving later on, or to allow plenty of cable if were needed to be reconnected several times down the road, maybe having to cut some off each time.

I see those loops all the time on traffic lights too.
Click to expand...


Aren't exterior loops on traffic lights like this just pretty much a drip loop?
 
It starts down the wire and falls off due to the speed going around the corners, or gets tired from going around in a circle.
The loops are for future movement of equipment.
 
Well, I am not one to nay say the install as I have no idea. If this is common practice then there may be something to it. I just have never seen an install like that- always has been right into the box but this may be new specs.
 
When I was an apprentice I asked why the LV stuff was wired with loops. The answer I got was that it was in case the box or device had to be moved a few feet, it would be easy to do. Sometimes its easier to work in or on those boxes if they are moved several feet first, like from above a dropped ceiling to below on top of a ladder. Or, it may make something else easier to install if the box or device can be moved a few feet and then replaced.

Or we may have been the one's installing the box or device and put it in the wrong place....

I really don't think that little loop is going to stop much lightning. In fact, if it creates any impedance, the loop may become a spark jump point and fuse open and catch fire.
 
Status
Not open for further replies.
Top