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Discussion Starter · #1 ·
We are replacing a range exhaust and found that the original wall line is in a corrugated metal sheath with only a black and a white wire, also in Bendy metal sheaths ...
I googled and found this is BX wiring. It is an old house but was rewired (and there are grounded outlets - 3 prongs through out the house) in the 1970s.

I can't figure out how to tell if it has a "grounding strip", or something else that will allow it to serve as a grounded line.


What should I be looking for?

Thanks
 

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Semi-Pro Electro-Geek
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You'll see the bonding strip at the ends of the cables, at the boxes. The strip sticks out and is often folded back along the cable. If you can't find a bonding strip there, it doesn't have one - and it's not grounded.
 
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Thanks for the reply

Are you saying that there will be 3 things sticking out from where the metal sheath has been removed? White, Black and something else?
More or less. If it's installed the usual way, then it's folded back and wrapped around the armor inside the connector. Here are pics:

https://www.doityourself.com/forum/electrical-ac-dc/586205-bonding-strip.html

http://www.city-data.com/forum/house/2511088-electricians-3-prong-outlet-not-grounded-4.html

https://i15.photobucket.com/albums/a352/TonyPE/P1080701.jpg
 
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Discussion Starter · #5 ·
My Bx has a clamp attached to the end of it, hard to tell if it is holding a ground. Is there a way to test the wall line for grounding the way we test our outlets to make sure they are grounded- some gadget???
 

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The BX or similar corrugated sheath cannot be tested electrically for proper grounding. You have to inspect it visually.

If there is enough slack in the wires at the outlet box, you might be able to withdraw the end of the BX cable far enough to inspect it for the grounding strip.

You can run a separate unsheathed ground wire of the same size from the outlet box in question down to the panel with the breaker for this branch circuit, down to a fat ground wire (grounding electrode conductor) coming out of the main panel for a ground rod or exiting water pipe, or (new) over to an outlet box that has a proper ground to its power source.
 

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A "Handy Husband"
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The NEC required Type AC cable manufactured after 1959 to contain the aluminum bonding strip. If the house was rewired in 1970 I would be confident the cable has the bonding strip and is a compliant ground.
 
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