Abstract: An electrical switch assembly including a plurality of main electrical switches, an operating device for opening and closing the main switches, and a single interrupter switch connected in parallel with the main switches and operable by the operating device. The interrupter switch opens only after any of the main switches opens, so that the single interrupter switch serves as the arcing contacts for all of the main switches. The operating device may include a shaft which is rotatable to operate the main switches and which is shiftable longitudinally to operate the interrupter switch. The shaft may carry a radially projecting follower pin slidable within a fixed guide slot shaped to insure the desired sequence of operation of the plurality of main switches and the interrupter switch. The interrupter switch, which may be a conventional circuit breaker, is a self-contained unit physically separate from the main switches.