Abstract: An apparatus for visually indicating abnormal phase relationships between incoming or outgoing phases for a plural phase device, comprised of a plurality of light emitting means interconnected between phases by a logic circuit arrangement whereby the various combinations of on/off indicators present a coded, visual presentation representing the specific mismatch condition of the network. The invention encompasses the concept of incorporating the indicating circuitry within the multiple phase device enclosure and providing an aperture in the enclosure so that the indicators may be viewed without the necessity of gaining access to the interior of the device and exposing individuals to the danger of high voltage/current circuits.