A piezoelectric sensor assembly is for an electrical system. The electrical system includes a sensor attachment assembly and a number of electrical conductors. The sensor attachment assembly includes a sensor housing and a fastening member for fastening the sensor housing to a corresponding one of the electrical conductors. The piezoelectric sensor assembly includes a processor enclosed by the sensor housing, a piezoelectric sensor element, a wiring assembly electrically connecting the piezoelectric sensor element to the processor, an insulating member coupled to the piezoelectric sensor element and being structured to extend outwardly from the sensor housing to engage the corresponding one of the electrical conductors, and a mounting enclosure structured to mount the piezoelectric sensor element and the insulating member to the sensor housing.