Feeding out to the side of a Switchboard

Status
Not open for further replies.
F

faldy15

New User
Location
Los Angeles
Occupation
Distributor
I'm a distributor and i've got a customer who purchased a Square D Speed-D switchboard (NEMA 1). Not sure why but he ended up drilling holes in the load side (right side if facing switchboard) to feed out to his subpanels instead of coming out of the top. Inspector didn't say its illegal, but wants something stating that it is ok to do. I think he needs a loadside wireway in order for it to be legal. Anyone know of any NEC reasons why this would or would not be ok?
 
As long as all the internal parts can still be accessed from the front, rear, or other side and there were no manufacturers instructions prohibiting it there is no problem.

With that said, your best bet is to contact SQ D and ask them for a letter, just telling your inspector you checked on a code forum might not get the results you're looking for.

Roger
 
IMO it's common to make holes where you need them if the provided KOs are not.
Not blocking or interfering with anything of course.
Never gave it a second thought.
 
flashlight said:
IMO it's common to make holes where you need them if the provided KOs are not.
Not blocking or interfering with anything of course.
Never gave it a second thought.
Click to expand...
I think the OP is talking about floor standing switchboards with removable side and rear panels. The busses in some of the switchboards I have installed were only accessible from the side if it was mounted against a wall.

Roger
 
Strange fact. With panel boards (not switch boards) UL actually only Lists the guts. That’s why you can buy a retrofit kit that you can mount into any enclosure. The enclosures of course must meet NEC not UL. So holes are fine in that. Switchgear on the other hand is Listed as an assembly so that may not be allowed technically although it falls under the principle of de minimus (don’t sweat the small stuff).

Drilling bus bar on the other hand is a very touchy area. From an engineering point of view as long as you don’t take away too much material and do it correctly following engineering standards for doing so, there is no issue. This is commonly done when using bus bars in an NEC context because of the much larger ampacity available and bus bars are cheap if you don’t mind the construction issues involved. In that case it’s like wiring...you are fabricating so no limits as long as NEC doesn’t specifically prohibit it and you are using sound design and construction practices. BUT again...if you are drilling holes in someone’s Listed bus bars that are a component of an assembly it converts the assembly to 508 (not 508A) so technically requires paying a UL inspector to bless it on site. Years ago of course before UL 1066 existed and switchgear fell under ANSI exclusively and was technically outside NEC (NESC purview) you could freely ignore the Listing since it was never Listed. In switchgear this is still the de facto situation most of the time anyway.
 
Status
Not open for further replies.
Top