Stranded Ground Cable: Does It Need a Clamp at Panel?

[Tom in Seattle]

My QO panel has two small knockouts about 1/4" in diameter on either side of the top center knockouts. Can those be used for the ground cable that attaches to the copper plumbing? I was watching an episode of Ask This Old House and the electrician ran his ground cable wiring through a 1/2" knockout and used a metal clamp. My ground cable will go straight in and attach next to the main neutral lug.

Thanks.

 

[Aceman]

Can those be used for the ground cable that attaches to the copper plumbing?
Thanks.

Yes, those guys using clamps are just wasting parts. That's what those prepunched 1/4" holes are for....

And if you don't have enough or don't think those holes are in the right spot, drill your own.

 

[Tom in Seattle]

Thanks. That's what I thought since my current panel just has a hole drilled in the corner.

 

[hh76]

Yes, those guys using clamps are just wasting parts. That's what those prepunched 1/4" holes are for....

And if you don't have enough or don't think those holes are in the right spot, drill your own.

I began using clamps in one of the KO's, rather than the small holes. Had an inspector make me change one out saying that the wire needs to be secured when entering a box. Didn't argue, just began installing the 50cent parts rather than risking $20 in time to re do another.