Abstract: Disclosed herein is a sensor assembly (10) for attachment to an electrical conductor (5), which includes a base (20) having a cavity (22) and a pair of detector housings (30) extending from the base (20). The detector housings (30) are laterally spaced and substantially parallel and are provided to receive a magnetic field detector. An electronic circuit card (70) is disposed within the base cavity (22) and is operatively coupled to the magnetic field detectors. Additionally, an auxiliary circuit card (90)) that contains logic for detecting an arc fault may be provided for communicating with the electronic circuit card (70).