NFPA 780 required material

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123star123

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Hello I'am an italian electrical engineer that work in the world of the cooling tower. In our site we have to realize a Lightning Protection System in accordance to NFPA 780.

I read the NFPA 780 (edition 2004) and in the section 4.2 Materials is written as shown below:


4.2 Protection systems shall be made of materials that are resistant to corrosion or protected against corrosion.


4.2.2 One or more of the materials in 4.2.2.1through 4.2.2.3shall be used.
4.2.2.1 Copper.Copper shall be of the grade required for commercial electrical work and shall be of 95 percent conductivity when annealed.
4.2.2.2 Copper Alloys.Copper alloy shall be as resistant to corrosion as copper.
4.2.2.3 Aluminum.
(A) Aluminum shall not be used where contact with the earth is possible or where rapid deterioration is
possible.
(B) Conductors shall be of electrical grade aluminum.

Now my question is:

As per NFPA 780 and yout experience, Can I use hot dip galvanized steel? Hot dip galvanized steel is in accordance with point 4.2 (Protection systems shall be made of materials that are resistant to corrosion or protected against corrosion)

If this is possible where I can find this infromation on the NFPA standard?

Thanks

Bye
 
Julius Right

Julius Right

Senior Member
Occupation
Electrical Engineer Power Station Physical Design Retired
It is not permitted by this standard, I am afraid:happysad::
4.2.2 One or more of the materials in 4.2.2.1 through 4.2.2.3 shall be used.
"shall" that mean "it must".
3.2.5 Shall. Indicates a mandatory requirement.
Even copper or aluminum part has to be corrosion resistant. See:
4.3 Corrosion Protection.
 
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123star123

Member
Location
italy
Julius Right said:
It is not permitted by this standard, I am afraid:happysad::
4.2.2 One or more of the materials in 4.2.2.1 through 4.2.2.3 shall be used.
"shall" that mean "it must".
3.2.5 Shall. Indicates a mandatory requirement.
Even copper or aluminum part has to be corrosion resistant. See:
4.3 Corrosion Protection.
Click to expand...

Thank you very much for your response, now I have my second question:

In the ANNEX N of NFPA 780 - Informational References I see that there are some references to IEC standard. This IEC standard are parts to integrate the NFPA or are only for information?

I ask this because per IEC standard Hot DiP Galvanized Steel is an acceptable material and If IEC standard are to integrate NFPA 780, I can use HDGS

Thanks

Bye
 
Julius Right

Julius Right

Senior Member
Occupation
Electrical Engineer Power Station Physical Design Retired
Annex N "Informational References" states:
The following documents or portions thereof are listed here as informational resources only. They are not a part of the requirements of this document.
I don't know what are the material indications in the IEC standard of the referred list. However
IEC 62305-3 Protection against lightning
Part 3:
"Physical damage to structures and life hazard"
Table 5 "LPS [Lightning Protection System] material and conditions of use"
Galvanized steel-stranded or solid-is permitted ?in certain conditions.
Nevertheless, this standard is not mentioned in the above Annex N.
 
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