An alternator includes an external ignition protection system including a shaft rotatable about an axis. The shaft includes a slip ring end. A slip ring support is mounted at the slip ring end of the shaft. A slip ring cover is mounted to the shaft. The slip ring cover defines a slip ring cavity. A first slip ring end housing supports the slip ring cover. The first slip ring end housing includes a first plurality of openings. A second slip ring end housing is arranged axially outwardly of the slip ring end. The second slip ring end housing includes a second plurality of openings. The first slip ring end housing, slip ring cover and the second slip ring end housing define a labyrinth flow path that provides an air flow through the slip ring cavity and prevents passage of ignition inducing elements from the alternator.