Square D and QO breakers are closely related because QO is a premium product line manufactured by Square D, but they are not identical or interchangeable across all panels. While Square D produces both the elite industrial-grade QO series and the standard residential Homeline series, they feature completely different physical dimensions and bus bar clips. A generic reference to a "Square D breaker" requires identifying whether it belongs to the QO line or the Homeline tier.
1 votes
Marked as accepted