olemus
väikese takistusega latt või juhe elektrijaotussüsteemis

Wiktionary:
an electrical conductor that carries a large current, especially one that is part of a power distribution system; typically a thick strip, or a tube, of copper or aluminium

piltlikult
https://duckduckgo.com/?q=busbar&t=h_&iax=images&ia=images

ülevaateid
https://en.wikipedia.org/wiki/Busbar

http://www.messung.com/blog/benefits-of-using-iec-61439-standard-in-electrical-busbar-systems/