Challenger Panel

[Rick 0920]

Is the wall of the can really thick enough to get the 250.8(A)(5) two threads engagement?

While it isn't the prettiest thing in the world, the easiest thing to do is remove some ground wires and pigtail them to a single hole freeing up however many the OP needs. This was suggested by an earlier poster.

Good question. I don't know if it is thick enough to meet that requirement. It is something I have done many times over the years on work that has been inspected. Maybe that has been something that has gotten past my inspectors. The small ground bars have always tightened down well and haven't stripped the threads.

 

[Little Bill]

Most, if not all, panel cans have holes predrilled for additional bars to be added. I don't recall seeing a raised spot that is any thicker than the rest of the can. So drilling and tapping new holes isn't a problem.

 

[James L]

Having 2 screws, each engaging 1 full thread, gives you 2 threads - no?

 

[ptonsparky]

Having 2 screws, each engaging 1 full thread, gives you 2 threads - no?

I've wondered that myself.
We've all seen the factory bonding screws on A/C units. Those make you wonder about the two thread issue being relevant.

 

[Little Bill]

Having 2 screws, each engaging 1 full thread, gives you 2 threads - no?

I don't think that's how it works

 

[James L]

I don't think that's how it works

Error is in the eye of the beholder

 

[James L]

I've wondered that myself.
We've all seen the factory bonding screws on A/C units. Those make you wonder about the two thread issue being relevant.

Heck, even the bonding screw in a typical panel probably doesn't engage 2 full threads

 

[ptonsparky]

As I see it the box would need to be 15 to 16 gauge minimum.

 

[mopowr steve]

They wouldn't be floating as they are mounted directly to the can. They don't have to connect to the neutral bar as it should be bonded to the can already.

Yeah, should be. If the bonding screw was installed or it is a service rated ONLY panel.

 

[Strathead]

Most, if not all, panel cans have holes predrilled for additional bars to be added. I don't recall seeing a raised spot that is any thicker than the rest of the can. So drilling and tapping new holes isn't a problem.

Good point. If I were the inspector, I would accept that argument.