Drilling of LBs

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Alutiiq Eng

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Location
Charleston, SC
In order to install a NEMA 4X enclosure for surge protectors, we drilled two (2) holes in the side of a 2" LB and installed two (2) Myers hubs and two (2) 6 inch 3/4" rigid conduit stub outs. The conduit stub outs will have Myers hubs installed to connect to the NEMA 4X enclosure.

I have researched the NEC and cannot find any reference to drilling LBs. Does this violate any NEC?s Articles? See below picture
 
steve66

steve66

Senior Member
Location
Illinois
Occupation
Engineer
You are no longer using the LB as an LB, so I'm not sure the listing matters. But with no valid listing left, I'd say it is up to the AHJ to decide if this is acceptable or not.

Personally, if it were my call, I wouldn't think it would be much different than drilling any other enclosure. (I may have to eat my words if the picture is ever posted!!)

Edit: Why didn't you just use reducers in the two existing holes on the LB??? I assume you just plugged them.

Steve
 
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Rockyd

Rockyd

Senior Member
Location
Nevada
Occupation
Retired after 40 years as an electrician.
Can't imagine why you you drilled the 2" LB? They were never designed to be used in said manner. I see it as a violation all the way around.
 
Dennis Alwon

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Alutiiq Eng said:
I have the picture, but I cannot embed images into my post. How do I "turn on" the "allow" image tag ?[/QUOTE]

Is the image on your hard drive or on the web? For some reason, it is a bit tricky to do it from the hard drive with the new system . Open an account at shutterfly or photobucket- it is free and upload to there and then enclose as an image by pasting the url using this icon above [IMG]http://forums.mikeholt.com/images/editor/insertimage.png
Click to expand...
 
Dennis Alwon

Dennis Alwon

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Location
Chapel Hill, NC
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Retired Electrical Contractor
Getting a picture from your hard drive. Here is what I have to do for some reason. I use this icon
attach.png


Then up near the top of the box that appears click load file. Choose another file so that there are 2 files available. Now close that out bu hitting done. Now click on the arrows next to the same icon as above and choose the file you don't want. Preview the post and it should be the one you want. I don't know why but that is what I have to do.
 
weressl

weressl

Esteemed Member
Location
Texas by the Gulf, geat crab, great shrimp
Alutiiq Eng said:
In order to install a NEMA 4X enclosure for surge protectors, we drilled two (2) holes in the side of a 2" LB and installed two (2) Myers hubs and two (2) 6 inch 3/4" rigid conduit stub outs. The conduit stub outs will have Myers hubs installed to connect to the NEMA 4X enclosure.

I have researched the NEC and cannot find any reference to drilling LBs. Does this violate any NEC?s Articles? See below picture
Click to expand...

  • An LB is a conduit fitting to facilitate wire pulling and conduit direction change, it is not for the purpose to house any devices.
  • Modifying any listed devices in a manner that is not described in the installation instructions will void its listing.
 
iwire

iwire

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Staff member
Location
Massachusetts
Alutiiq Eng said:
In order to install a NEMA 4X enclosure for surge protectors, we drilled two (2) holes in the side of a 2" LB and installed two (2) Myers hubs and two (2) 6 inch 3/4" rigid conduit stub outs. The conduit stub outs will have Myers hubs installed to connect to the NEMA 4X enclosure.

I have researched the NEC and cannot find any reference to drilling LBs. Does this violate any NEC?s Articles? See below picture
Click to expand...

From the UL General directory


Field Modifications​


What happens to the Listing if a UL-Listed product is modified in the field?
An authorized use of the UL Mark is the manufacturer?s declaration that the product was originally
manufactured in accordance with the applicable requirements when it was shipped from the factory. When
a UL-Listed product is modified after it leaves the factory, UL has no way to determine if the product
continues to comply with the safety requirements used to certify the product without investigating the
modified product. UL can neither indicate that such modifications ??void?? the UL Mark, nor that the
product continues to meet UL?s safety requirements, unless the field modifications have been specifically
investigated by UL. It is the responsibility of the Authority Having Jurisdiction (AHJ) to determine the
acceptability of the modification or if the modifications are significant enough to require one of UL?s Field
Engineering Services staff members to evaluate the modified product. UL can assist the AHJ in making this
determination.
Click to expand...
 
K8MHZ

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
weressl said:
  • An LB is a conduit fitting to facilitate wire pulling and conduit direction change, it is not for the purpose to house any devices.
  • Modifying any listed devices in a manner that is not described in the installation instructions will void its listing.
Click to expand...

I have a bad pic on my phone of an LB cover with an Edison base in it. I have never seen one like it before, it's ceramic and turns an LB into a luminare. It is in a building built in 1908 that I looked at a couple days ago.
 
don_resqcapt19

don_resqcapt19

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Staff member
Location
Illinois
Occupation
retired electrician
K8MHZ said:
I have a bad pic on my phone of an LB cover with an Edison base in it. I have never seen one like it before, it's ceramic and turns an LB into a luminare. It is in a building built in 1908 that I looked at a couple days ago.
Click to expand...
Crouse had both Edison bases and receptacles for their conduit bodies for a long time. Not sure if they still make either
 
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Alutiiq Eng

Member
Location
Charleston, SC
Picture of Drilled LB

Picture of Drilled LB

As you can see, we have a 2" rigid conduit coming from concrete foundation into the bottom of the LB. The LB is installed into a concrete structure, fire barrier sealed, with a GUAB with sealing cover inside the concrete structure. A new NEMA 4X enclosure for surge protectors are required to be install on the exterior of the structure. Only low voltage (12VDC) shielded signal cable will be installed in this conduit pathway. Surge protectors will be installed in the new NEMA 4X enclosure. No splices or terminations will be in the LB. The LB is used as a ?pass-thru?. Cable from head-end equipment will enter bottom of LB, enter NEMA 4X enclosure to surge devices, off the output side of surge devices electrical (low voltage) wires will exit the new NEMA 4X enclosure through the upper conduit into structure. Once all wiring has been installed the GUAB will be packed with Chico fibers and Chico compound, sealing the conduit off
To clarify this picture, the 2" rigid conduit and LB were existing and in-place prior to the need to install a new NEMA 4X enclosure on the face of the concrete structure. Again, no splices or terminations will be in the LB. Shield cable from the ?head-end? equipment will enter the LB bottom from an underground duct bank, exit the bottom ?? stub off into the NEMA 4X enclosure and connector to surge protectors. From the output side of the surge protectors, shielded cable will exit the enclosure through the top ?? stub into the LB and into the concrete structure. All conduit and conduit bodies will be watertight and continue to provide physical protection for the low voltage shielded cable.
Drilled LB.jpg
 
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nhfire77

Senior Member
Location
NH
IMHO it's wrong as for reasons previously stated. Very creative, but wrong. Why dont you use a pull box, that would have taken just bit longer.

(PS: your picture is gonna be on the bulliten board in my office, great conversation piece, no disrespect intended)
 
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