How to Cover 1" and larger knockouts?
 

I understand that all un-used knockout holes must be covered in some way. How would you go about covering knockouts larger than 3/4"? I assume there must be larger covers for these. All I can find at the local hardware stores are covers for the 1/2" and 3/4" holes, I think I have a 1 1/2" and a 2" hole to cover up in both a sub panel and a sub-meter.

This is in regards to an inspection needing to be done on the recent replacement of the furnace. I know my main panel and adjacent subpanel would setup a ton of red flags if any inspector comes in to check it out so I'd like to fix the "red flags" before they even get here.

Would having large open knockouts in panels un-related to a furnace replacement be grounds to fail an inspection?

Electrical supply house should the different size knockouts you need.

I don't know if the inspection would include the inspector looking at the electrical panel, but it would be a good idea anyway to plug those. Better to be safe than sorry. You can find the appropiate "plugs" at an electrical supply house

I figured the electrical supply house would be the response. I'm looking to do this work in the next week or so over Christmas while I have time off from work, so maybe I will make the knockouts the last item on my list to do. I was just curious if I should be worried about it or not, but it makes sense to have them covered up for when the inspector takes a look at it.

With my luck he will simply take a look in the panel at the labeling for the furnace and the size of the breaker and call it a day, so a lot of this work would be for nothing (but to be safe).

Two fender washers and a bolt with a nut works well for a KO seal. Any bigger than say 1" or so, I have snipped the corners off of a couple of 4" square covers and bolted them together.

Is that UL listed??? :wink:

Haha, I was thinking about manufacturing something to cover the holes. Though in response to theKCtermite, it isn't UL listed though would this be better than not covering them at all?

Some inspectors realize that sometimes you have to improvise to make it safe. If you have many supply houses around (like here on Long Island), then there's no excuse not to do it with listed devices. Have a Happy Holliday. pete

I was kidding. That's why I put the winking smiley face next to my comment. Listed/approved is better, but sometimes an improvised fix is just fine for the intended purpose.

The big box stores do sell KO seals, up to 2" I believe.
Those morons are probably open all day tomorrow.

If my memory serves me right and its sometime questionable, but I think that in these parts the openings must be covered with a material of equal gauge to the enclosure! Thinking back, I don't believe that I've ever seen a plug that met this requirement.

To be code compliant for an enclosure and be listed....:) Try a knockout seal as Speedy mentioned.. You generally get these with rain proof enclosures so you can close off the hub opening then bottom feed opposite the hub.

http://www.garvinindustries.com/cate...subcatid_E_544

1" knockout plugs are quite common about everywhere where a decent electrical department is located. Bigger than that when I'm in a pinch my favorite is two knockout reducing washers and the appropriate size plug that I might have on hand.

http://www.garvinindustries.com/prod...?path=RW-3.jpg