Abstract: A perimeter security system that includes a perimeter enclosure having a moving portal closure, a plurality of electronic sensors on the enclosure and a security system with conductors for electrically connecting the sensors in series to detect a security branch at one or more of the sensors. A connector arrangement for making series connection between the sensors across the closure when closed includes a pair of connector bodies for mounting at juxtaposed positions on an edge of the closure and on an edge of the enclosure opposed to the closure edge. Male and female electrical contacts are disposed on the connector bodies and connected to the security system for mating engagement when the closure is closed and disengagement when the closure is open. Cam fingers on one of the connector bodies and cam guides on the other connector body automatically align the bodies and the electrical contacts as the closure is closed.