[kbsparky]

I am looking at some plans for an aircraft hangar job. They are calling for a static discharge grounding grid, and reference NFPA 409 in the specs.

Each hangar bay will have (2) floor mounted receptacles ERICO B165 where one can "plug in" a cable and attach it to the fuselage of the aircraft to prevent static charges from building. These grounding ports will be interconnected with bare copper wire cad-welded together into a grid, and finally terminated to several 3/4 x 10 ground rods.

They don't tell my what size wire to use -- only to check NFPA 409. Is there something in there that I need to know that is not part of the NEC?

 

[wildleg]

nope. no real suprises in there. you can read it online tho, just like the NEC and most of their other documents, you just need to create a login. its free.

http://www.nfpa.org/aboutthecodes/list_of_codes_and_standards.asp?cookie_test=1

 

[captkirk]

I vaugly remember doing a grounding grid for a fuel storage tank at an airport. we cadwelded about 15 rods and used #4 copper.

 

[kbsparky]

Copy that on the 15 ground rods. Exactly the number in this spec.

As for the #4 wire, I noticed the words "Counterpoise wire" -- something that is used for radio tower grounding grids??