wireday
Senior Member
- Location
- New England
- Occupation
- Master electrician
I have 4-11/16 boxes mounted on wall, they have 1/2 and 3/4 knockout holes, I want to put 1-inch LFMC can I knock out to 1-inch ?
4-11/16
- Thread starter wireday
- Start date
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
You certainly can. They do make them with 1" ko's also.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
Why would you think you couldn't?
OldBroadcastTech
Senior Member
- Location
- Western IL
- Occupation
- Retired Broadcast Technician
Greenlee 1-3/8 punch
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
Believe it or not, a large percentage of the inspector/AHJ community would call it a "listing violation"
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
On what basis?Believe it or not, a large percentage of the inspector/AHJ community would call it a "listing violation"
Are you allowed to strip insulation off of conductors?
A listing only applies to the product as it left the factory.
According to UL it is up to the AHJ to determine if a field modification makes the item no longer suitable for its intended purpose.
To my knowledge an enclosure has the same listing requirements whether it has blank sidewalks or knockouts for field removal.
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
You would have to ask them. I've heard this countless times in the field. Some inspector even said once that you cannot make you're own KO's in a panel enclosure.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
What happens when you have a "Hoffmann" box?Some inspector even said once that you cannot make you're own KO's in a panel enclosure.
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
I know the argument is silly. We never use panels enclosures that even have KO's so guess that we cannot make any either. Same with large pull boxes and wireways. I asked this inspector why he would say it "violates the UL listing". He couldn't answer that one.
Master Nater
Member
- Location
- Midwest
- Occupation
- Electrical Magician
some inspectors just want to rule the world, and have entirely too much time on their hands...
herding_cats
Senior Member
- Location
- Kansas
- Occupation
- Mechanical Engineer
WHRE did you find steel boxes with no KO's? Please tell me. I have a huge demand for stage power boxes for live music. I have been looking for no KO steel boxes for years. Even better with no screw holes other than EGC pigtail
herding_cats
Senior Member
- Location
- Kansas
- Occupation
- Mechanical Engineer
Damn. I wish I had found this back in 2019. I searched everywhere but I was looking for 1900s 4square. This is awesome thanks.Here's one:
The problem with KOed boxes is that they get banged around, the KOs get pushed into the box and break off, shorting out. Life is rough for stage power components. they get destroyed. 4 111/16 is a better box for this.
Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
That inspector would be wrong and the code can be used in this case. 314, doesn't require boxes to be listed.Believe it or not, a large percentage of the inspector/AHJ community would call it a "listing violation"
Same here, we never used cabinets with factory KO's. There was not a factory KO in any of the cabinets in the picture below.
VirutalElectrician
Senior Member
- Location
- Mpls, MN
- Occupation
- Sparky - Trying to be retired
That's for the wireless electricity. 802.120 and 802.240 I think are the standards.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
- Location
- Illinois
- Occupation
- retired electrician
Can you show me an instruction from a box manufacturer that says you can not make your own holes in their boxes? Without that, 110.3(B) does not apply. Of course 110.2 applies to everything.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
Exactly, thats how it works. Unfortunately many inspectors dont understand that and think you need to be given permission to do something.