100a waterpipe #12mc

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newservice

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The house built in 1960 has a water pipe grounding conductor that is a steel sheath- MC style. hard (very hard!) drawn copper conductor which appears to be a #10 in size. It is about 15 feet long. Am tempted to leave it alone and just replace the clamps, my thinking is the steel sheath also serves to conduct to the water pipe. I know code allows the MC to serve as the ground in <6' lengths, but with the bare conductor inside, it should be ok.
Anyone agree or disagree?
 
What you've described is likely cable armor which is used for physical protection of the GEC. The current NEC requires protection for conductors smaller than #6. In the 1959 NEC T250-94(b) #2 or smaller SEC's would require a minimum size GEC of #8.
 
infinity said:
What you've described is likely cable armor which is used for physical protection of the GEC. The current NEC requires protection for conductors smaller than #6. In the 1959 NEC T250-94(b) #2 or smaller SEC's would require a minimum size GEC of #8.
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Cable armor, yes. Thanks. And pretty impressive, having the 1959 NEC section too.
I think to call it a #8 would be a stretch. I'm still puzzled why it is so hard to bend, more like steel than copper. Oh well, AWG of either probably isn't an 8, but will check before I chuck it and do over with a 6. Great reply.
 
newservice said:
Cable armor, yes. Thanks. And pretty impressive, having the 1959 NEC section too.
I think to call it a #8 would be a stretch. I'm still puzzled why it is so hard to bend, more like steel than copper. Oh well, AWG of either probably isn't an 8, but will check before I chuck it and do over with a 6. Great reply.
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Don't forget 8 solid is going to be smaller than 8 stranded.
 
iwire said:
Don't forget 8 solid is going to be smaller than 8 stranded.
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Yep, still it looks a lot smaller than an 8 even. I've seen plenty of the armored 6 solid going to water pipes before and this is just a LOT smaller than usual, even the armored part is smaller diameter. The conductor itself is made of titanium though (kidding) . I still think the armor counts for something as a conductor. By this time tomorrow it will be history and the inspector will have passed it, whatever I end up doing with it.
 
By now I'm sure everyone wants to know the rest of the story. The Armored Cable GEC was indeed # 8 solid. I replaced it with 6 stranded and two new pipe clamps, as I was replacing the whole service. Of course, this passed. $20 bought me 25' of #6 ,and a ground bar which I mounted on the panel for the phone and cable TV grounds. All done and inspected.
 
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