A sensor for a separable connector includes a plug body, one or more high voltage capacitors, one or more low voltage capacitors, and a low voltage connection. The plug body includes an insulating resin. The plug body can be inserted into the separable connector to encase a high voltage conductor disposed in the separable connector. The one or more high voltage capacitors are encased by the insulating resin and can be electrically coupled to the separable connector at a first end portion when the plug body is inserted. The one or more low voltage capacitors are electrically coupled in series to the one or more high voltage capacitors to form a capacitive voltage divider. The low voltage connection provides a low voltage signal corresponding to a high voltage signal present in the separable connector. Signal conditioning electronics or a memory may also be included.