How to determine the Bus Bar rating of a panel

[Love Aux Power]

More than often I find myself looking for the actual Bus Rating for a panel. How can I determine the Bus Rating if the manufacturer does not put it on the specs? I need it to determine the backfeed max allowable for a solar project.
The panel in question is Cutler -Hammer HP404040SH.

 

[jim dungar]

More than often I find myself looking for the actual Bus Rating for a panel. How can I determine the Bus Rating if the manufacturer does not put it on the specs? I need it to determine the backfeed max allowable for a solar project.
The panel in question is Cutler -Hammer HP404040SH.

Panelboard bus bars are not sized by any method you can use in the field. The current carrying capability of a panelboard is based on heat rise inside of the enclosure, so any given physical size of bussing could have multiple 'ampacities'.

Contact the manufacturer.

 

[Jraef]

That's a 400A panel. What part of the specs are you missing?

...
Enclosure
NEMA 3R

Security
Ring

Amperage Rating
400A


Line Lug landings for compression, lugs not included
...