Legal to Punch Another Knockout in Strip Light?

[bad_idea]

My long winded title pretty well says it. I bought (20) 2 Bulb 48" T8 LED strip lights I plan to mount directly to the bottom of the trusses (no ceiling). If I mount the lights centered on the truss (parallel to the truss) it blocks the factory knock outs in the light housing. Is it code compliant to make a new hole off center in the housing? That would allow me to mount the lights down the center of the truss, cable down the side of the truss and dropped into the top of the light. At some time in the distant future I plan to install a ceiling and would like all of the wiring in the attic space.

 

[markhm]

Punching a new hole in the fixture voids the UL listing. Code requires fixtures be (UL) listed.

In reality, it is done often. It doesn't sound like a safety issue assuming it is properly done. But if you have an electrical inspection at some point, an inspector would be allowed to say you have an unlisted fixture and reject you.

 

[bad_idea]

I built the garage last summer and am finally getting around to running the electrical (time and money deficit). I am going to pull an electrical permit. Considering the money I have invested in the lights, I don't want to take the risk of getting rejected. So, what other options are there to mount these lights to the bottom of the truss with the wiring entering through the top of the fixture?

 

[OccupantRJ]

You could mount them across trusses instead of parallel to allow the knockouts to be used. On mine, I just popped holes where I needed them. Government, stay off my lawn!

 

[markhm]

Suspend them below truss and wire thru factory k/o. Get your inspection.

Then you can raise them, plug the k/o holes and put new holes where it works for you.

 

[Leaflessshadetree]

You can also nail up some blocks so they are offset but still parallel to the truss.

 

[Platonic Solid]

This is done all the time in the field with a greenlee punch. If you do it neatly, no inspector would ever know or care. Many strip light housings come with knockouts on the back, side and ends. Since LED retrofit bulb strip light housings have no internal components and only house the wires, I can't think of any UL issues with adding a 7/8" dia. hole at a location that's convenient for your installation. Just use common sense with respect to hole location so there's enough clearance for the nut of the cable connector (or whatever device you're installing) and you're not diminishing the structural integrity of the housing or interfering with installed housing parts.

Note: Using the 3.32" width of the Maxlite 4ft retrofit housing, you don't have enough room to do what you're stating. 3.32" - 1.5" truss = 1.82" / 2 = 0.91". This puts the edge of the 7/8" hole right at the housing bend line - offering no clearance for the cable connector nut.

 

[Jim greengo]

Punching a new hole in the fixture voids the UL listing. Code requires fixtures be (UL) listed.

In reality, it is done often. It doesn't sound like a safety issue assuming it is properly done. But if you have an electrical inspection at some point, an inspector would be allowed to say you have an unlisted fixture and reject you.

As long as it lands under the cover that protects wires I dont see an inspector complaining about it myself anyway.

 

[nsula_country]

Greenlee or hole saw KO where needed (correct size). Use proper cable or conduit fitting with a locknut. If existing KO have been knocked out, install a filler plug (no tape!). Done.

CT

 

[mike93lx]

If you have an inspector digging that deep, you are going to fail anyway

 

[ard]

lol. Legal? Who cares?

If it is inspected, ask the inspector. Otherwise doesnt matter (unless you are a licensed contractor.)

(Edit: not saying to go and violated codes....just that there seems to be an obsession with 'to code' in some very very minor and arcane points. Moving a KO a few inches in an otherwise open wiring channel is one of them.....)

 

[dledinger]

Most inspectors around here wouldn’t know one hole from a hole in the ground...if you get what I’m saying.

 

[teamextreme]

This is done all the time in the field with a greenlee punch. If you do it neatly, no inspector would ever know or care. Many strip light housings come with knockouts on the back, side and ends. Since LED retrofit bulb strip light housings have no internal components and only house the wires, I can't think of any UL issues with adding a 7/8" dia. hole at a location that's convenient for your installation. Just use common sense with respect to hole location so there's enough clearance for the nut of the cable connector (or whatever device you're installing) and you're not diminishing the structural integrity of the housing or interfering with installed housing parts.

Note: Using the 3.32" width of the Maxlite 4ft retrofit housing, you don't have enough room to do what you're stating. 3.32" - 1.5" truss = 1.82" / 2 = 0.91". This puts the edge of the 7/8" hole right at the housing bend line - offering no clearance for the cable connector nut.

^This. Particularly the second paragraph. You would have to mount the fixtures off-of-center on the truss to provide enough room on the back of the fixture for a new KO.

 

[bad_idea]

If you have an inspector digging that deep, you are going to fail anyway

I hear you on that one. I just want to avoid getting failed for an item that will cost me a fortune.

I appreciate you all's confidence in punching a new hole not being a big deal. Unfortunately I am that guy that will get popped for dumb stuff. This is a 'Risk vs. Reward' deal for me - I risk having an inspector tell me all of my light housings are garbage for the reward of an easier install. I'll sort a good solution that follows code, or at least can be easily reversed if I get popped.

 

[OccupantRJ]

Ask the inspector. You will then have your ducks in a row.

 

[ard]

I hear you on that one. I just want to avoid getting failed for an item that will cost me a fortune.

I appreciate you all's confidence in punching a new hole not being a big deal. Unfortunately I am that guy that will get popped for dumb stuff. This is a 'Risk vs. Reward' deal for me - I risk having an inspector tell me all of my light housings are garbage for the reward of an easier install. I'll sort a good solution that follows code, or at least can be easily reversed if I get popped.

Ask the inspector. You will then have your ducks in a row.

Or OP is just being OCD and needs it to 'be to code' for whatever reason.

Cant ask an inspector if there actually is no inspector....

 

[rharman]

Mount them off-center. Just sister some 2x4 blocks on the joist.

 

[bad_idea]

Mount them off-center. Just sister some 2x4 blocks on the joist.

You my friend are a genius. Best part is I have a pile of scrap lumber from when I built the shop last year. Thank you.

 

[Platonic Solid]

Mount them off-center. Just sister some 2x4 blocks on the joist.

You my friend are a genius. Best part is I have a pile of scrap lumber from when I built the shop last year. Thank you.

Not knocking anyone’s Mensa credentials, but isn’t that what Leaflessshadetree said in post 6?​

You can also nail up some blocks so they are offset but still parallel to the truss.

 

[bad_idea]

What can I say, it takes me a few to catch on.

 

[larry_g]

Punching a new hole in the fixture voids the UL listing.

I'd sure like a cite on this. Having gone through a few NRTL certifications I don't think this is true.

lg
no neat sig line

 

[alfredeneuman]

i'd sure like a cite on this. Having gone through a few nrtl certifications i don't think this is true.

this! ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 

[Innovate1]

I can't imagine it being a problem to punch another hole as long as there are no other issues (wires pinched, things like that). They make electrical boxes with no holes that you have to punch holes in so how can that be wrong? And how would the inspector ever know that the hole wasn't a knockout. Once the fitting is in place there is no way to tell.

But the added wood sounds easier.

 

[alfredeneuman]

More about the listings thing....
Some jobs for municipalities I've worked on specified for a minimum conduit size of 3/4".
The light fixtures that they specified only came with 1/2" KOs.
I guess by knocking them out to 3/4" I violated the listing requirements?

 

[Falcon67]

If I was going to put up rows of 4' fixtures, I'd also consider tying them together with conduit end for end and raising the whole mess as a unit to the joist, then coming out of one end with the feed.

Also done the spacer block thing - see the light at the far distance in the pic

 

[Jim greengo]

this! ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

What he said.

 

[NUTTSGT]

I can't imagine the inspector would have issue with it. They make junction boxes with out knockouts so you can place them where you need them.

 

[BD1]

What about wiring light with a cord and plug end. Mount cord up against trust and plug into receptacle.


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[MattT]

What he said.

What y'all said

I've been told that to maintain a UL listing whatever you stick in the hole must also be UL listed. This was for enclosures so maybe there are different rules for light fixtures...................................

 

[MrSurly]

Are we NOT going to mention the two-post lift through the ceiling?


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[SGKent]

Doesn't someone make UL approved knockout seals?

 

[egdede]

Drill it and fill it with a listed bushing (as noted above):

https://www.platt.com/platt-electri...NAP+BUSHING&SectionID=9&GroupID=113&CatID=978

 

[rharman]

Not knocking anyone’s Mensa credentials, but isn’t that what Leaflessshadetree said in post 6?​

It was the word "sister" that made the difference...

 

[Norcal]

Doesn't someone make UL approved knockout seals?

UL does not approve anything, they list it, if it says "UL approved" then you can be sure you have a counterfeit product.

 

[mike93lx]

Are we NOT going to mention the two-post lift through the ceiling?


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Is that not UL listed?

 

[MrSurly]

Is that not UL listed?

Well the OSB may not be.....


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