Concentric KO's

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SceneryDriver

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NJ
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Electrical and Automation Designer
:rant: I fail to understand why manufacturers can't get concentric KOs right. Twice yesterday, the entire KO ring blew out while I was trying to remove just the center. Now I have sets of 2" --> 1" and 2" --> 1-1/2" reducing washers installed. I hate these things with a passion. Just let me punch my own holes if it's so hard to engineer a concentric KO that isn't terrible; at least then I know they'll always come out the right size. That's why I always buy enclosures with no KO's.

The concentric KO's in 4" sq. boxes work great. Why can't that technology be applied to breaker panels and ATS enclosures?!

<rant off/>


SceneryDriver
 
Ponchik

Ponchik

Senior Member
Location
CA
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Electronologist
I guess you had a fight with couple of KOs and you got KOed out by both???

It is ok. Have a beer or two.

I know, sometimes all come out but you just wanted a 1" and now you have to get a 3" to 1" reducer. :lol::lol:
 
infinity

infinity

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New Jersey
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Journeyman Electrician
SceneryDriver said:
:rant: I fail to understand why manufacturers can't get concentric KOs right. Twice yesterday, the entire KO ring blew out while I was trying to remove just the center. Now I have sets of 2" --> 1" and 2" --> 1-1/2" reducing washers installed. I hate these things with a passion. Just let me punch my own holes if it's so hard to engineer a concentric KO that isn't terrible; at least then I know they'll always come out the right size. That's why I always buy enclosures with no KO's.

The concentric KO's in 4" sq. boxes work great. Why can't that technology be applied to breaker panels and ATS enclosures?!

<rant off/>


SceneryDriver
Click to expand...

I agree with you, many of them are terrible to remove. Often I will bend them slightly and then cut each section of the concentric ring with my dykes to isolate one little tab at a time. The tangential type usually on Square D stuff seem to be better but IMO when you're done the holes are somewhat sloppy.
 
Dennis Alwon

Dennis Alwon

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IMO, this happens periodically when the punch is getting dull. Not sure how they check these things but I usually find that they work okay most of the time.
 
K8MHZ

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
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Electrician
An EC friend I know hates them so bad, he uses a hole punch on them and doesn't even try the screwdriver method.

For me, some of them come out fine with care, but I have had some that were horrible. I have had some that were so bad, the bottom of the panel would dent before the ring would pop.
 
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Carultch

Senior Member
Location
Massachusetts
SceneryDriver said:
:rant: I fail to understand why manufacturers can't get concentric KOs right. Twice yesterday, the entire KO ring blew out while I was trying to remove just the center. Now I have sets of 2" --> 1" and 2" --> 1-1/2" reducing washers installed. I hate these things with a passion. Just let me punch my own holes if it's so hard to engineer a concentric KO that isn't terrible; at least then I know they'll always come out the right size. That's why I always buy enclosures with no KO's.

The concentric KO's in 4" sq. boxes work great. Why can't that technology be applied to breaker panels and ATS enclosures?!

<rant off/>


SceneryDriver
Click to expand...

I dislike premanufactured conduit entries too. It means you have to know exactly where your conduits go, if you are trying to plan alignment of your equipment in advance of having it available. Also an issue if another trade is going to build your conduits embedded in a wall or slab, in advance of your equipment showing up on site. And good luck finding this information on a datasheet. It also means that if the over 250V rules apply, you need additional grounding means that you wouldn't need if you could make your own hole.

Another issue is if the manufacturer anticipates a different mix of sizes than you do. I've seen equipment that has a field full of 1/2" only KOs and only one larger KO. All I wanted to do was 1" in and 1" out.
 
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don_resqcapt19

don_resqcapt19

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Illinois
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retired electrician
For panel enclosures, I always specify that they do not have any knockouts. I much prefer to put the holes where I actually want them and not have to deal with the prepunched ones that really don't match up with any of the standard installation methods.
 
infinity

infinity

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don_resqcapt19 said:
For panel enclosures, I always specify that they do not have any knockouts. I much prefer to put the holes where I actually want them and not have to deal with the prepunched ones that really don't match up with any of the standard installation methods.
Click to expand...

I couldn't agree more unless were running strictly MC cable to concealed panels (probably not an issue for you). :D

We have in the past ordered KO's only on one end of the panel so you could use it either with or without KO's by flipping it over which gives some flexibility depending on the installation.
 
ActionDave

ActionDave

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Durango, CO, 10 h 20 min from the winged horses.
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don_resqcapt19 said:
For panel enclosures, I always specify that they do not have any knockouts. I much prefer to put the holes where I actually want them and not have to deal with the prepunched ones that really don't match up with any of the standard installation methods.
Click to expand...

Man oh man do I agree. I think it should be opt in for pre punched panels instead of opt out.
 
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