a breaker interlock device adapted to mechanically resist switching a handle of a first circuit breaker from an OFF position to an ON position when a handle of a second circuit breaker is in an ON position, said breaker interlock device comprising a first faceplate and a second faceplate, said first faceplate comprising a breaker escutcheon receiving recess adapted to receive a breaker escutcheon of said first circuit breaker, said breaker escutcheon receiving recess at least partially defining a slidable plate receiving slot adapted to encircle a slideable plate, said slidable plate adapted to resist motion of said handle of said second circuit breaker from an OFF position to said ON position when said first circuit breaker is in said ON position, said breaker interlock device defining a cavity adapted to receive said handle of said first circuit breaker, said breaker interlock device defining an opening adapted to receive said handle of said second circuit breaker, said breaker interlock device defining a plurality of slots, said plurality of slots adapted to move said breaker interlock device relative to said first circuit breaker, said cavity defining a first longitudinal axis, said first longitudinal axis substantially parallel to a second longitudinal axis defined by said first circuit breaker, said opening defining a third longitudinal axis substantially parallel to a fourth longitudinal axis defined by said second circuit breaker, said third longitudinal axis substantially perpendicular to said first longitudinal axis.