What is the difference between sub feed lugs, through feed lugs, and sub feed breakers?

Search FAQs

Issue:
What is the difference between sub-feed lugs, through-feed lugs, and sub-feed breakers?

Product Line:
Panelboards

Environment:
Applies to NQ and NF Panelboards

Resolution:

Sub feed lugs are a replacement set of lugs used in place of the normal main lugs of a panelboard. They allow the installer to subfeed to another panel or device. Sub-Feed Lugs can be used on main lugs interiors.
Feed through lugs are a second set of lugs mounted opposite the mains end on the end of the bussing. Feed-Through Lugs can be used on main lug or main breaker interiors.
Sub feed breakers are branch breakers mounted opposite the mains end on the end of the bussing. They are used when a branch breaker amp rating is required that is higher than can normally be accommodated on the interior. Sub-feed Breakers can be used on main lugs or main breaker interiors.

See the below picture as a reference.