Can I use the knockouts right next to my ground bar, or does it permanently block them? I'm wondering if I am allowed to run conductors across/over the ground bar and if I can put EMT connectors in these knockout holes.Ground bar here.

  • Will these be THHN wires or NM-B with the interior cable clamp? Are there any other ground bar sites in the panel? They typically give you 2-3 sites (site=screw holes pre-tapped to mount the bars, though you can always drill and tap your own). Nov 11, 2020 at 21:03
  • This will be THHN. Yes, there are other ground bar sites. I already have a 21 slot ground bar at the top and I probably don't need another, but I went ahead and bought another. Just trying to understand the consequences of bar placement.
    – tnknepp
    Nov 11, 2020 at 23:22
  • Are these bars made for this panel? A little odd to see only 1 mounting screw on a bar that long. Nov 12, 2020 at 4:26
  • Yes. There are multiple locations for the bar. Some locations allow two screws to be used (center hole then has a nub in it), others allow single center screw to be used (two end holes both have nubs in the to prevent the bar from turning).
    – tnknepp
    Nov 12, 2020 at 10:11

1 Answer 1


I have used many panels just like this I usually don’t move the buss but it is easy to do the 2 screws are usually 10-32 self forming screws that hold the buss in place move it if you would like, code has no requirement on the position.

If you can’t or don’t feel comfortable with that location move the buss. I always have a set of drill/taps for box modifications they drill and tap in one quick operation if using a tapped hole it’s a lot easier to put the screws in and code legal with a 32 pitch screw.

Never use self tappers inspectors look for those and will red tag a job if they see one. Self forming machine screws are different and have the 32 pitch most commonly 10-32 but I have found some 8-32’s used by different mfg’s.

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