An operating mechanism for opening and closing a heavy duty electrical switch is provided. The mechanism includes a switchclosing spring means, a switch-opening spring means, a manually actuated first means for charging both spring means when said switch is in an open condition, and a manually actuated second means operative, only when both of said spring means are charged, to effect discharge of the switch-closing spring means and closing of the switch. The switch-opening spring means can be either manually or automatically discharged so as to open the switch. Automatic discharge of the switch-opening spring means occurs only when a predetermined condition exists in the electrical system.