Punching new holes in main breaker panels

[jeffelectric1992]

We recently had an inspection on a service upgrade fail in Chicago for a reason I have never had cited before.
The Inspector failed the installation because the installer had punched a two inch opening in the back of the new tub for the service
entrance pipe and didn't use the existing concentric knockouts. The inspector stated that this was a violation of the panels listing.
I can find no information from the panel manufacturer that would support the inspectors claim.

 

[infinity]

The inspector is making up his own code. Panel enclosures are permitted be punched for new KO locations. There is no violating the listing of the panel enclosure. In fact many enclosures come with no KO's at all.

 

[roger]

I will be a little more blunt than Rob, the inspector is a moron

 

[ActionDave]

The panel is listed as it is when it leaves the factory. If the inspector is going to reject you for punching your own hole he has to reject for the same reason if you use the pre punched knock out.

 

[LarryFine]

The inspector stated that this was a violation of the panels listing.
I can find no information from the panel manufacturer that would support the inspectors claim.

Two points:

1. There's a reason you can't find any supporting info.

2. It's the inspector's responsibility to support his claim.

 

[CoolWill]

I bet that same inspector is on this forum arguing about how deadly rigid couplings are.

 

[electrofelon]

It's really a shame when inspectors waste time on this type of thing. Why don't they spend their limited time resources looking for actual safety issues?

 

[rc/retired]

I bet that same inspector is on this forum arguing about how deadly rigid couplings are.

No, if the inspector was on this forum he/she would not have made such an idiotic call.
A rigid coupling IS deadly if you throw it hard enough at someone.

Ron

 

[don_resqcapt19]

Where were the field punched KOs located in reference to the point where the conductors that run through those KOs land on the terminations?
Often this is a violation because you don't have the required bending space. The factory ones are located to comply with the bending space. Not saying this is a problem with this installation, but it could be.

Also remember that Chicago uses a highly modified version of the NEC...there were about 150 pages of amendments when they converted the 2017 NEC into the 2018 Chicago electrical code.

 

[Fred B]

There would be 2 ways that might be an issue, If the new punched out opening location made for a conductor bend radius to tight (408.55), or it made an overlap of multiple pre-existing KO's creating a weakened enclosure or made for poor securing of the conduit or connector (110.12,), Might look like a clover leaf cutout.
But adding a new non-factory KO in of itself a non-issue, done all the time, especially when the conduit position doesn't or can't be made to lineup with a factory KO.