Square D

Square D is a major American manufacturer of electrical equipment and a flagship brand of Schneider Electric, which acquired the company in 1991. Founded in 1902, it is an industry leader in electrical distribution, circuit protection, and industrial control products for homes and businesses.

Core Products:
Circuit breakers (including the famous QO and Homeline lines)
Electrical panels and load centers
Safety switches and disconnects
Transformers and switchgear
Motor control and automation systems