what size junction box? - Electrician Talk - Professional Electrical Contractors Forum

tavwtby · 08-07-2009, 02:24 PM

I have an industrial application where I have to connect 262mcm locomotive wire to copper bus bars in a junction box. It is three phase, 1000v 500A. I am not sure on 1) the size of the junction box to use, and 2) the spacing of the copper bus bars inside. It is a feed thru, coming from a generator going to another panel. Any info or leads would be appreciated.

paul d. · 08-07-2009, 04:46 PM

contact a QUALIFIED electrical contractor. you're welcome.

**MDShunk** · 08-07-2009, 05:29 PM

I'm thinking that you don't need a junction box. You're going to be building a genuine cabinet that will require a UL field evaluation or will need to be manufactured in a UL certified panel build shop.

paul d. · 08-07-2009, 05:41 PM

minor hijack; i've installed lots of custom built cabinets/ j-boxes over the years in comm. and ind. settings. i dont recall any of them " u.l. certified ". gotta have the u.l. sticker to be certified ??? just wondering .

**MDShunk** · 08-07-2009, 06:20 PM

Quote:

Originally Posted by paul d.

minor hijack; i've installed lots of custom built cabinets/ j-boxes over the years in comm. and ind. settings. i dont recall any of them " u.l. certified ".

I think we all have. Doesn't make it right.

Bob Badger · 08-07-2009, 08:16 PM

I do not think the NEC requires this to be listed unless it is for a specific location (Wet, classified, etc.)

That said, the AHJ still has to approve it and they do not have to.

Control Freak · 08-07-2009, 08:38 PM

Quote:

Originally Posted by Bob Badger

I do not think the NEC requires this to be listed unless it is for a specific location (Wet, classified, etc.)

That said, the AHJ still has to approve it and they do not have to.

Something similiar coming up on my job...
We have 3/0 MI cable coming from a shaft into a box w/copper detail changing over to 500s for a generator feed. We are using a 36 by 36 box about 24 inches deep. Hope this helps!!!!!