- Location
- New Jersey
- Occupation
- Journeyman Electrician
I have a panelboard with 2" wide by 1/4" thick copper bus (the straight portion in center of the photo). How would one determine the ampacity of that bus?
I did take a look at that table online, what would be the temperature rise for a panelboard?
While is doesn't apply to this application, the NEC specifies the ampacity of copper bus at 1000 amp per square inch in 366.23(A).
UL requires 50C max. rise
I looked at that number too which would make this 2"x.25" bus good for 500 amps which to me seems about right when I compare it the bus in some other panels on site. The bus rating of this panelboard is supposed to be 1200 amps.
Rob, so this isnt anything you are modifying or making, just "double checking" a factory panelboard?
For copper, all of the panelboards and switchgear we have inspected thru the years usually
follows the 1000A per square inch cross-section rule. So for that panel it would be 500 A per phase.