Knockout or Not

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xlx

Member
Hello, Does anyone know about the requirements for making knockouts in electrical equipment. I have been told that if I make a knockout in a panel that it "Voids the UL Listing" This makes sense but what about junction boxed gutters antique equipment ect. does anyone know where I might find guidelines about this? Thanks for your help

Daniel
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: Knockout or Not

Welcome to the forum Daniel I have never heard of this and I really do not think that is true.

We order all our panel tubs and most of our junction boxes larger than 6" x 6" without any factory KOs. We do this so we can punch into the enclosures wherever we want without factory KOs getting in the way.

In my opinion this would be the same as saying cutting a piece of EMT voids the UL listing. ;)

[ August 19, 2004, 04:40 PM: Message edited by: iwire ]
 

sandsnow

Senior Member
Re: Knockout or Not

Danliel
It seems as though there may be more to this story. Electricians have been making holes in enclosures for nearly a century

Was it a special type enclosure involved?

If a panelboard, did the conductors enter where the re was insufficient bending radius?

Curious & :confused:
 

xlx

Member
Re: Knockout or Not

Thanks for your replies,
The enclosure where I was cited on was a 30 amp RV Service panel with meter, disconnect and outlet. One of my men cut a 3/4" knockout in the back of this panel at the top. Although this would not be a good practice with larger conductors the conductors were #10 so I didn't feel bending space was a problem. I accepted the correction though and contacted the inspectors supervisor and asked for more information. OK, I argued with him about it(politely)! :D He said that I was not to cut knockouts in any electrical equipment. Crazy Huh?! :confused: More feedback is appreciated.
 

sandsnow

Senior Member
Re: Knockout or Not

If where the KO was made is not the field wiring compartment you could have a problem. The pedestals I've work on or inspected had a definite point where conductors were to enter.
But "any electrical equipment" ???? I have no idea the reasoning behind that statement.
 

xlx

Member
Re: Knockout or Not

I used standard running thread and lock nuts. I know this was not a proper choice. I should have at least used sealing locknuts. It's the other equipment thing that i am most concerned with because if they hold me to it things will be difficlut. Especially retrofitting old equipment.

Daniel Bradford

edited by moderator to remove contact information

[ August 20, 2004, 02:52 PM: Message edited by: don_resqcapt19 ]
 
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