K8MHZ
Senior Member
- Occupation
- Electrician
Stated so eloquently
Nobody will be able to show you as far as panel cans are concerned.
Roger
So the whole thing about violating a UL listing is moot, as there was none to violate, correct?
Punching holes in panels voids the UL listing ??
- Thread starter powerfill
- Start date
- Status
So the whole thing about violating a UL listing is moot, as there was none to violate, correct?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Of course not, but the drill motor and bits that you use to make the holes must be listed for that purpose.
We can't have just any old hole-making tools, you know. :angel:
kwired
Electron manager
- Location
- NE Nebraska
I seen some holes made by oxy-acetylene torch before.
One school I did some work the original installer of the current main gear apparently had benders that could bend 3 inch RMC but apparently couldn't afford a 3 inch KO punch, most of their holes were cut with a torch. :roll:This work was installed mid 1960's if that matters to anyone.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
What I think is that this is a combination of ignorance, hubris, semantics and misinterpretation.
It IS indeed technically a "violation" of the UL listing of ANY electrical enclosure to make any hole in it, IF THE HOLE IS NOT USED FIR A UL LISTED FITTING OR CLOSURE. So this guy is reading a PART of that rule and jumping to a conclusion, or misinterpreting it altogether because he doesn't understand.
That last part may also be the semantics issue; the result of you using the term "knock-out", which is a pre-punched hole with a filler slug still installed. YOU cannot add a "knock-out", that is something that can only be done at the factory, because in order for the enclosure to even pass a Type 1 classification, there is a mechanical test called a "rod entry" test. The details are fuzzy for me now, but it's something like this; a 1/4" diameter steel rod something like 6' long and dropped from something like 10' cannot penetrate the enclosure at any point, INCLUDING any factory installed knock-outs. So even if YOU had some sort of tool that could make an actual knock-out, you cannot subject it to the UL rod entry test so you cannot add it without violating the UL listing.
But, what I THINK you meant was a HOLE, not a knock-out. Holes are fine, as long as you COMPLETE the task by installing an appropriately listed conduit fitting; hub, male adapter, pulling ell, flange, whatever. What you CANNOT do is punch s hole, and LEAVE IT OPEN. IF you DONT USE IT, you must use a closure plug or plate that is also appropriately UL listed for the task. So for example if you punch, cut or burn a hole, then realize it's in the wrong place, you cannot just slap a piece of duck tape on it and move on. You have to use a correctly applied closing fitting. For Type 1 boxes that's usually just the little solid slugs with the screw-on bar on the inside, but if your box is 3R, you have to find and use a closure device listed as 3R or 4.
The hubris of this AHJ is that he either made a judgement error based on his own ignorance and misinterpretation but is backing it up with bluster, or he knew damned well what you meant, but is f-ing with you for using the wrong semantics. Either way, that makes him either a dope or an A-hole.
It IS indeed technically a "violation" of the UL listing of ANY electrical enclosure to make any hole in it, IF THE HOLE IS NOT USED FIR A UL LISTED FITTING OR CLOSURE. So this guy is reading a PART of that rule and jumping to a conclusion, or misinterpreting it altogether because he doesn't understand.
That last part may also be the semantics issue; the result of you using the term "knock-out", which is a pre-punched hole with a filler slug still installed. YOU cannot add a "knock-out", that is something that can only be done at the factory, because in order for the enclosure to even pass a Type 1 classification, there is a mechanical test called a "rod entry" test. The details are fuzzy for me now, but it's something like this; a 1/4" diameter steel rod something like 6' long and dropped from something like 10' cannot penetrate the enclosure at any point, INCLUDING any factory installed knock-outs. So even if YOU had some sort of tool that could make an actual knock-out, you cannot subject it to the UL rod entry test so you cannot add it without violating the UL listing.
But, what I THINK you meant was a HOLE, not a knock-out. Holes are fine, as long as you COMPLETE the task by installing an appropriately listed conduit fitting; hub, male adapter, pulling ell, flange, whatever. What you CANNOT do is punch s hole, and LEAVE IT OPEN. IF you DONT USE IT, you must use a closure plug or plate that is also appropriately UL listed for the task. So for example if you punch, cut or burn a hole, then realize it's in the wrong place, you cannot just slap a piece of duck tape on it and move on. You have to use a correctly applied closing fitting. For Type 1 boxes that's usually just the little solid slugs with the screw-on bar on the inside, but if your box is 3R, you have to find and use a closure device listed as 3R or 4.
The hubris of this AHJ is that he either made a judgement error based on his own ignorance and misinterpretation but is backing it up with bluster, or he knew damned well what you meant, but is f-ing with you for using the wrong semantics. Either way, that makes him either a dope or an A-hole.
- Occupation
- Licensed Electrician
There has been enough evidence that this guy is on the wacko side of things. Who is his boss? Give him a call and ask if he agrees.
kwired
Electron manager
- Location
- NE Nebraska
His wife probably has no idea
meternerd
Senior Member
- Location
- Athol, ID
- Occupation
- retired water & electric utility electrician, meter/relay tech
Been at many meetings with UL, manufactures, vendors, etc. Manufacturers tend to frown on ANY modifications to their gear. Liability. UL only tests as "from the factory". If modifications are made, UL would have to do a field visit to "re-certify" the equipment (if it's UL listed in the first place). But the bottom line is that the AHJ, being POCO, building inspectors, etc. are not always expert in field modifications, and some are extra picky just because they don't want to be "second guessed" by their bosses if a problem occurs on a piece of equipment they inspected. Arguing sometimes works, but other times it just makes matters worse. My suggestion would be to have the AHJ justify their complaints with documentation, mfgr. written approval, etc. I guess the bottom line is money...is it cheaper to fight the opinion or just make the AHJ happy and do it their way. Your choice. AHJ's are like anyone else...CYA!
donaldelectrician
Senior Member
Seriously , I would think that the AHJ has his hands out and needs a little Grease .
That is how that language sounds to me .
Don
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
His wife probably has no idea
It took a while for that to sink in, but when it did, I laughed... :slaphead:
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
At least in countries where corruption and graft are rampant, the guy could just tell you what the "fee" would be and you could get on with it. Here in the US, where you could get in trouble for suggesting such a thing and likewise so could he, it's tough for an inspector to make a dishonest buck.
sparkyrick
Senior Member
- Location
- Appleton, Wi
Exactly what it is.
You can get some boxes and cabinets with no KO's at all, maybe ask those making this rule to try to enter those without drilling or punching a hole
ALL of our bigger j-boxes have no factory KO's. That AHJ is trying to have too much of the "A" part.
Last edited:
01jacobite
Member
- Location
- US ny,ny
I guess it may depend on your local codes and their amendments to the nec. Because in NYC amend. 110.2 and 110.3 as it pertains to manufacturers listing is strongly enforced. And I've actually been written up for something similar.
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