Ground Bars Are Required In All Panels (main Service Panels Include Ground And Neutral). Ground Bars Must Be Purchased Separately For Main Lug Panels, Since Theground And Neutral Must Be Separated. All Of Our Eaton Ground Bar Catalog Numbers Start With Gbk, Followed By The Number Of Circuits In The Ground Bar. To Be Sure You're Selecting The Correct Ground Bar, Divide The Number Of Circuits In Thepanel By 2 And Pick The Closest Numbered Ground Bar. For Example, A 20 Circuit Panel Would Require A Gbk10p. Both Our Br And Ch Loadcenters Use The Same Groundbars.