Did an inspection of new home recently and found that the ground clamp attached to the incomming copper water supply pipe is made of metal and knowing that disimilar metals corrode over time, is it required to be called out?
I have called this out in other homes but it seems that all/most electricians use them. Surely they would know that disimilar metals corrode.
Personally I would not make an issue of it. I see white type metal clamps all the time on copper incoming water lines. Can’t say as I have ever seen one causing a problem and I have been inspecting since 1991!
as an additional note, in newer construction where the cold water line is bonded to the steel gas pipe leading at hot water heater all those clamps are the white metal variety, for what its worth.
I’ll bet there’s a non-corrosive plating of some kind on those clamps, or an alloy rather than plain mild steel.
I’m posting a picture of a brass clamp on a galvanized steel ground rod with a rather tarnished copper grounding conductor, installed around 1965. I called for a repair here, but the worst corrosion is where the conductor is in contact with the dirt.
That is an interesting point, Raymond. On an outboard or a boat hull, the sacrificial Zinc is bolted to the leg or the hull because with electrolysis, especially in salt water, it corrodes faster than any of the other metal components. So the clamp will rust before the coper pipe.
Corrosion can impede the quality of the ground. I don’t make an issue out of it but I always recommend my clients to replace it. This is the same thing as copper hangers or copper nails used to support the copper pipe. If the pipe will be supported with galvanized hangers, I think everybody will call it out. Builders know that corrosion will occur there but it will take years. Bottom line is they can put clamp for about half price ($2 versus $4) and save some money :mrgreen: </IMG>
I have seen more lose clamps on the pipe and loose set screws on grounding clamps and bonding clamps. To me that is more of an immediate concern. Usually I just tighten the clamp.
