dissimular metals

[Larry G]

An electrical inspector is telling us to remove all of the steel staples we used to secure aluminum MC cable because he is concerned about the galvanic effects of dissimular metals.
Has any one else come across this? :roll:

 

[charlie b]

Re: dissimular metals

Galvanic action requires the physical contact of two dissimilar metals. You are not telling me that you put the staples so deep into the cable's insulation system that the staple has made contact with the conductors?

There is no basis for this Inspector's concern. If he pushes the point, ask for a code citation, or ask to see the supervisor.

 

[bphgravity]

Re: dissimular metals

That section of the NEC (110.14) only applies to electrical connections of conductors. I also don't think 300.6 qualifies.

 

[paul]

Re: dissimular metals

What did he recommend replacing them with? Aluminum staples or aluminum bx straps? I wonder where one goes to get such devices. :roll:

 

[steve66]

Re: dissimular metals

Chalie B:

I'm guessing since its MC cable that it has an outter alumnium shell.

But I agree, a little corosion between a nail and the shell won't hurt anything. And once a little corosion gets between the two, the corosion will stop since they won't be in contact any more.

Steve

 

[bensonelectric]

Re: dissimular metals

Maybe we shouldnt use GRC threaded directly into aluminum boxes

 

[paul]

Re: dissimular metals

Originally posted by bensonelectric:
Maybe we shouldnt use GRC threaded directly into aluminum boxes

Or die-cast EMT fittings.

 

[jim k]

Re: dissimular metals

Originally posted by Larry G:
An electrical inspector is telling us to remove all of the steel staples we used to secure aluminum MC cable because he is concerned about the galvanic effects of dissimular metals.
Has any one else come across this? :roll:

Um, you might point out that steel and aluminum are practically next to each other in the galvanic series. That means that there's not likely to be a galvanic effect.

Using steel staples on aluminum-clad cable is fine.

- Jim K

 

[sandsnow]

Re: dissimular metals

Originally posted by Larry G:
An electrical inspector is telling us to remove all of the steel staples we used to secure aluminum MC cable because he is concerned about the galvanic effects of dissimular metals.
Has any one else come across this? :roll:

Stuff like this worries me. Where did he get this? Some code seminar? Did he come up with it on his own?
Reminds me of some inspector who told me wirenuts were devices when counting box fill.
A correction such as the original post lessen the credibility of inspectors.