BBC Brown Boveri M633 Motor Circuit Breaker is a historical BBC/Brown Boveri motor-protection device used to interrupt motor current in electrical installations. A cataloged variant is M6331S10-16-25A, rated for 660 VAC with Ith (thermal current rating) of 16 A. This M633 family, originally from BBC Brown Boveri and now part of ABB's heritage, is intended for protection of motor circuits requiring a dedicated circuit-breaker for overload or short-circuit conditions.
