ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

I have no problem with a 'spec' .... and I have a confession to make:

I almost always use the 'quick reply' box. This seems to specifically address my comments to the previous poster ... when that is not always my intent.

In this case, two posters mentioned #6; I thank both of you for responding, and I understand both approaches.

For general discussion purposes, if the intent is to cause a breaker to trip should someone get a shock off the siding, I'm not sure I'd approach the matter the same way. I don't think there's anything in the code that would require a wire larger than #14, I don't think you need to use lugs, and I would want the wire to land on the bussbar in the panel. That's how it looks to me, anyway. I don't see the metal siding as being part of the grounding electrode system at all.

Reno:
The siding is NOT any part of the grounding electrode system, the discussion is regarding bonding the siding, or that's what I thought.

Bonding conductors are sized based on the OCP of the circuit that is likely to energize the conductive material. Hence, as I said on page 1, the largest OCP IMHO would be the service main, and in actuality the OCP at the utility primary. With the al. siding 'floating'...it could become energized by a fault, ranging from a 15 amp branch, to the 100+ service main, or the utility primary. Now, bond the al. siding, a fault trips the branch feeder, or...the al. siding vaporizes.

Sticking with a resi job, IMHO other that the service, the largest OCP would likely be the HVAC, or possibly a hot tub at 50 amps, hence a #10, or good old #6 for a 200 amp service.

Again, this scenario is not (to the best of my knowledge) addressed within the NEC directly, but..."likely to become energized" could be interperted many ways.

I follow you now. Another poster mentioned running the wire to a ground rod ...