Galvanized Pipe vs Copper due to Copper Theft

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ground25

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As we all know, copper theft is an issue especially for those of us in wireless communications. I recently talked with someone that is proposing the use of a 3 1/2" galvanized post in place of a #2 solid conductor for a down lead from a tower ground bar to the earth ground ring (roughly about 12-15'). I'm looking for some numbers concerning the inductance and conductivity of galvanized steel vs copper. Any ideas?
 
ground25 said:
As we all know, copper theft is an issue especially for those of us in wireless communications. I recently talked with someone that is proposing the use of a 3 1/2" galvanized post in place of a #2 solid conductor for a down lead from a tower ground bar to the earth ground ring (roughly about 12-15'). I'm looking for some numbers concerning the inductance and conductivity of galvanized steel vs copper. Any ideas?
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if you made the post part of the ges I don't see a problem.

<added> as long as it goes 8 feet into the ground.
 
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Interesting idea. A copper strip has much lower impedance at lightning frequencies than a conductor. It may be similar for a steel tube, might be as simple as the difference between steel and copper conductivity.
 
You can look here in the downloads section. It makes comparsions between steel conduit and copper wires for equipment grounding. Not the same as lightning, but maybe a starting point. Also I know that lightning protection systems often use the steel beams of the building as down conductors.
Don
 
don_resqcapt19 said:
You can look here in the downloads section. It makes comparsions between steel conduit and copper wires for equipment grounding. Not the same as lightning, but maybe a starting point. Also I know that lightning protection systems often use the steel beams of the building as down conductors.
Don
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Is it tested and approved for the purpose?

If not then fawgeteaboutit... the AHJ won't pass it.

If it is for Lightning Protection then aluminum products are approved downcomers.
 
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Laszlo,
The steel columns of buildings aren't tested for the purpose and they are used as down conductors. It doesn't look like this is an actual lighting protection system as I have never seen solid conductors used on those sytems. If this is just for the protection of the tower and its equipment, it may very well be a design issue and not really covered by any codes.
Don
 
don_resqcapt19 said:
Laszlo,
The steel columns of buildings aren't tested for the purpose and they are used as down conductors. It doesn't look like this is an actual lighting protection system as I have never seen solid conductors used on those sytems. If this is just for the protection of the tower and its equipment, it may very well be a design issue and not really covered by any codes.
Don
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"The steel columns of buildings" are identified in NFPA 780 as acceptable components of a lightning protection system. They are tested and identified for THAT(structural steel) purpose, therefore acceptable.

Solid condutors HAD been used as lightnting downcomers and may have been, at that time, acceptable to the AHJ. Existing installations would be grandfathered, but new installations should follow NFPA 780. Solid, flat straps are now identified as a recognized component.

"If this is just for the protection of the tower and its equipment, it may very well be a design issue and not really covered by any codes." Protection against what? If it is protection against lightning, then NFPA 780 is applicable and depending on your local ordinance, it is enforceable.





'NFPA? 780​




Standard for the
Installation of Lightning Protection Systems
2008 Edition
This edition of NFPA 780, Standard for the Installation of Lightning Protection Systems, was prepared by the Technical Committee on Lightning Protection and acted on by NFPA at its June Association Meeting held June 3–7, 2007, in Boston, MA. It was issued by the Standards Council on July 26, 2007, with an effective date of August 15, 2007.​





The 2008 edition provides requirements for surge protective devices to be installed at all power service entrances, at the entrance of conductive communications systems and antenna systems, and where an electrical or electronic system conductor leaves the structure.​



A new definition for Lightning Protection System is provided, which now includes “conductive structural members.” Clarification is provided relative to the use of ancillary metal parts that cannot be substituted for the main conductor. Strike termination devices include air terminals, metal masts, certain permanent metal parts of structures, and elevated conductors. Revisions now clarify that metal masts and overhead ground wires are included in the requirements of Chapter 4.'​
 
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Solid condutors HAD been used as lighnting downcomers and may have been, at that time, acceptable to the AHJ.
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I am assuming that this is a new installation.
then NFPA 780 is applicable and depending on your local ordinance, it is enforceable.
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How many cities or other units of government have adopted 780? I am not aware of any in my area.
Don
 
don_resqcapt19 said:
I am assuming that this is a new installation.

How many cities or other units of government have adopted 780? I am not aware of any in my area.
Don
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Still, the question remains: protection against what?

Are there any other lightning protection standards than 780? If not then how would the property insurer would determine what kind of hazard exposure does he have in any particular case? Rememebr that THAT was the primary dirver behind the NEC!

Since surge protection is addressed extensively in this dosument and the NEC does require it, the two are now linked even more than before.
 
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