A shunt trip mechanism includes a ratchet facility added to a self-contained, line potential stored-energy operating mechanism of a circuit interrupting device. Operation of the ratchet facility releases the stored energy to operate the device. A portion of the ratchet facility may also be operated to reset the device if it has previously been operated by either the shunt trip mechanism or the operating mechanism's current-responsive elements. The main portion of the shunt trip mechanism is at ground potential and is mechanically tied to and operates the ratchet facility by a movable insulated strut. The strut is moved by the shunt trip mechanism upon the occurrence of an event such as transformer overpressure. A ground level handle may be operated to reset the device whether it was operated by the operating mechanism or the shunt trip mechanism.