ECN Forum Forums General Topics of the Trade General Discussion Area EMT locknuts for Grounding

I'm glad everything worked out with the inspector. Now if he can just take care of the issues on the other thread without getting too riled up....he is the same guy, I think ...Oh well
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OK,Here's a couple more for anyone that still doesn't believe in the screwdriver. Thanks to Joe Tedesco for sending them over

These are stills from an NFPA Expert Training Video.








(I wonder if the screwdrivers have a warning label on them not to strike them?)

[This message has been edited by electure (edited 11-20-2004).]

So I looked up 256.96 (A) out of the NEC
it didn't read the same. whare did that come from?

Bucketman, this is showing that the locknut (as part of the fitting) actually cuts into the metal through any non conductive paint per the requirement of 250.96, as well as showing a screwdriver tightening it is a common and accepted technique.

Roger

Locknut torque wrenches? ;-)

Bucketman,
If you're talking about the text image rather than the pictures, it came from
"Soares Book of Grounding", published by the International Association of Electrical Inspectors, not the NFPA (and incidentally available through ECN's bookstore).
It's considered to be the most authoritative book available on grounding and bonding.

Well, since I'm here anyway, here's what happens when the fitting is tightened (maybe with a wrench?) and the locknut doesn't pierce the paint. Just a 20A 120V circuit that had a ground fault. These were both tight.


1. This KO was slightly oversize, looked like someone went a notch too far with a step drill



2. Here's the conn on the other side of the box. This KO was the proper size.




3. Inside shot of the conn in #2




[This message has been edited by electure (edited 11-22-2004).]