Using a chain link fence as GEC??

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onelinediag

Member
Location
United States
This is a photo of what appears to be a chain link fence being used as a GEC, (on a construction site).

Presumably the fence posts are driven in to the earth a few inches, every few feet. Is this acceptable/standard practice? Wouldn't this constitute a connection to the earth at multiple points (each fence post for the length of the fence)?

Thanks...
 

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ceb58

Senior Member
Location
Raeford, NC
I think you are correct. Pretty common set up around communication sites I have worked on.

Agreed, all of our communication sites have all of the corner post and gate post bonded to the ground ring along with tower legs, A/C units, generator and you if you stand still long enough in one place:cool:
 

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
It is being bonded. It also common around substations with high voltage over head lines.
 

Carultch

Senior Member
Location
Massachusetts
Could it be that the fence is bonded to the grounding system and not being used a GEC?

How exactly does one bond a fence, and get every part of it to be electrically continuous in a code-compliant manner?

Do you need a split bolt or grounding U-bolt on every post, every brace pipe, every fabric segment, and every intricate fence fitting? Or do you just need to connect to major posts?

I'd imagine that there exists some amount of electrical continuity among the fence fittings and components, even if it isn't tested for such a purpose or installed by electricians.
 

iwire

Moderator
Staff member
Location
Massachusetts
How exactly does one bond a fence, and get every part of it to be electrically continuous in a code-compliant manner?

The one time I have to do this we had to put bonding jumpers between each vertical fence post and the horizontal pipe that ran along the top along with bonding jumpers at the hinge side of each gate.

We drilled the fence and bolted the jumpers into place.
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
How exactly does one bond a fence, and get every part of it to be electrically continuous in a code-compliant manner?

Do you need a split bolt or grounding U-bolt on every post, every brace pipe, every fabric segment, and every intricate fence fitting? Or do you just need to connect to major posts?.....
I used to have a copy of the whole R56 spec but I don't anymore. I found a link that gives a taste of what goes on in the places I've been involved, it is about half as detailed as the real deal....scroll down to page 68 if you want to skip right to the part about fences. http://www.buckeyejeeps.com/radio/docs/misc/R56_Grounding-Surge_Protection.pdf
 

onelinediag

Member
Location
United States
Yeppers! Enough cad welds going off to look like the 4th of July.

Thank you all for taking the time to respond.

Are we not concerned about voltage gradient? Does each fence post being connected to Earth place the fence at equal potential or does it constitute a difference of potential?

If this is acceptable, then why is placing multiple ground rods bad practice? Isn't it electrically the same thing? ie, if it think it would be interesting to see in schematic how this differs from having multiple GEC.

i dont mean to ramble...just trying to understand what the difference is.

Also, just because its common practice dosen't make it correct or safe.

Please expand...

Thanks,
One line diag
 

electricalist

Senior Member
Location
dallas tx
It's acceptable to have multiple (2) ground rods.
I'm not sure if I'm capable of fully understanding potential but if I put 1 lead from my tester in the hot side of my plug out side and the other lead to my fence it reads 109-110 so it's the potentially the same as a gec. But I don't have any idea why.
 

Tony S

Senior Member
Thank you all for taking the time to respond.

Are we not concerned about voltage gradient? Does each fence post being connected to Earth place the fence at equal potential or does it constitute a difference of potential?

If this is acceptable, then why is placing multiple ground rods bad practice? Isn't it electrically the same thing? ie, if it think it would be interesting to see in schematic how this differs from having multiple GEC.

i dont mean to ramble...just trying to understand what the difference is.

Also, just because its common practice dosen't make it correct or safe.

Please expand...

Thanks,
One line diag

That is the precise reason metal peripheral fence posts are bonded to the MET. In an outdoor substation the whole enclosed area should be an equipotential zone.

I don?t know about the requirement in the US but multiple rods equally spaced around the periphery is standard practice in the UK. Multiple rods over a wide area will form an excellent ground nest.

I?ve just done a design for a small 800KVA substation. 12 rods, 2 Ufer mats and the steel fencing all connected.
 

electricalist

Senior Member
Location
dallas tx
I had a new helper with me the other day and gave him the hammer drill with the ground rod driver and after ten minutes they ask does this have to go all the way in I think it's hitting rock,,,all I could do was laugh. I remember leaving the shop day after day and all we had to do was set t poles ,drive rods. Sledge hammer and sharp shooter.
 
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