Originally Posted By: Steve Costa This post was automatically imported from our archived forum.
Is it ok to ground a panel with a stranded, sheathed aluminum wire to the copper water pipe? Do you need a special fitting because of the dissimilar metals? Thanks, Steve
Originally Posted By: lewens This post was automatically imported from our archived forum.
Something tells me this is a ripe environment for galvanic action. All things needed are here. Dissimilar metals,a possibility of current and moisture.
Originally Posted By: Steve Costa This post was automatically imported from our archived forum.
The clamp was in a tight spot, could not get a good line of sight, I just stuck my camera up there and clicked away. I did write it up for the corrosion. My main concern was I had never seen stranded, sheathed aluminum used.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
The aluminum is OK if it is more than 18" off the ground. That keeps it off of ground rods but Al is OK in the house. You will be using a larger size, just like any other Al conductor vs copper. Stranding is normal for any insulated conductor over #10 although they do make bare #4, 6 and 8 cu.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Hard to tell, but it looks like the signs of corrosion are where the clamp is in contact with the copper pipe/rod … and not really at the lug for the AL wire (which looks like it separates the wire from the pipe/rod). So it appears the concern may be the clamp.
Was that in a damp area, because it looks like an indoor type small diameter pipe clamp for dry areas ... with a typical one shown below (written up as a concern/defect in wet/burried areas).
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Now if that was a outdoor/burried rated acorn clamp (shown below), I would be concerned about the direct contact between the AL wire and copper pipe/rod.
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Hey Steve … I missed the part about the clamp being on a water line … opps … just went from the pic which looked kinda like a ground rod. Same concern though, and it appears to be an issue with the clamp and not the wire.
And by damp/wet area I mean like a crawl space that has signs of significant water penetration and no cover over the subgrade (like a thin rat slab or moisture barrier).
Also, does it look like a really old install? That may not be too bad if it's been there for quite a while and there is only a small area with signs of corrosion, and it's pretty easy to just move it a bit to a clean section.
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong