With high voltage lines running above a chain line link fence

[Thepoteet]

With high voltage lines running above a chain line link fence, does the fence have to be grounded? I work for the army and I haven't heard of this being done and can't find it in the following code books NEC 2011 - NEC 2005. Is it posible that it is in another NFPA? Could you guys help point me in the right direction?

 

[WorkSafe]

The fence is installed into the ground, so wouldn't it already be "grounded?" Nothing in the NEC about this. If there were such a requirement, it probably would be in the NESC.

 

[Thepoteet]

Thanks

Thanks

I will check that out, the army does alot of projects that don't make any sense. I was asked to bid the job and from the second I was told about it, it just didn't make any sense about it.

 

[don_resqcapt19]

If you have access to a copy of the National Electrical Safety Code, there may be something in there. That is the code the utilities use.

 

[mivey]

Check with the POCO about the grounding requirements as well as the construction restrictions/requirements.

As for the grounding, the fence posts may or may not be adequate but it will depend on the voltage. The rule is to limit the current from electrostatics to 5 mA. This may require additional grounds and the POCO should be able to help with the details.

As for the code, see NESC 234G3 for above 98 kV:

NESC 243G3
For voltages exceeding 98 kV ac to ground, either the clearances shall be increased or the electric field, or the effects thereof, shall be reduced by other means, as required, to limit the steady-state current due to electrostatic effects to 5 rnA, rms, if an ungrounded metal fence, building, sign, billboard, chimney, radio or television antenna, tank or other installation, or any ungrounded metal attachments thereto, were short-circuited to ground. For this determination, the conductor shall be at a final unloaded sag at 50 oc (120 ?F).

 

[Hv&Lv]

go with the code number mivey posted, not the code number in the text box...

 

[mivey]

go with the code number mivey posted, not the code number in the text box...

I fat-fingered the code section in the box. I did not proof-read the scan either so "5 rnA, rms" should be "5 mA, rms" and "50 oc" should be "50 ?C"

 

[Thepoteet]

Thanks all for the reference to the NESC, I fianlly got a copy and see what I needed in black and white.