Using copper busbar in termination box

[winslowfam]

hi...we are designing a termination box using copper busbar for terminating the feeder cables instead of power terminal blocks. I have read through different articles in the code regarding termination, junction and pull boxes for guidance on sizing and wire bending space...but someone brought up a question about whether or not un-insulated copper busbar could be used in an enclosure for terminating these cables. I plan to use insulator standoffs, and provide guarding the connections. Is there a code reference that I need to consider regarding this design? Thanks.

 

[petersonra]

despite how common they are, the code is all but silent about the use of busbars other than acknowledging they are there.

unlike wires, they are not even required to be listed, and there are no ampacity charts for them.

it is unclear to me how one can calculate an SCCR rating for such an assembly.

 

[winslowfam]

I have found ampacity charts online from manufacturers of busbars, based on dimensions (thickness, width)...and noticed they state a short circuit current rating, too, but I haven't looked into that yet.

Thank you for your comments...

 

[cadpoint]

I' m having a little trouble understanding why your group is designing and not just going to a (NEMA) manufacture
of these like boxes. Just a quick e-search brought up both UL approved and NEMA boxes.

"Large electrical enclosures" SCE is one manufacture that build this type product. They have all their products with downloadable specified applications.

Good luck with your build.