A connector system for distributing power to daughter cards in a card cage includes a power connector for each card mounted on framework of the card cage. Each power connector has individual terminals connected to power conductors connected to a power supply and at least one terminal connected to a return path conductor. Each power connector includes a channel along which an active edge of the card is inserted and moved longitudinally from an open end, opposed from another channel aligned therewith, until the daughter card is fully inserted into the card cage, and signal transmission connectors along the back card edge mate with connectors of the backplane of the card cage. The daughter card is then locked in position; its power connector is then actuated, camming contact sections of its terminals into electrical engagement with contacts along the active edge of the daughter card. Each daughter card is thus powered and correspondingly disconnectable independently of the other daughter cards. An interference arrangement prevents the power connector from being actuated unless the card is locked in position, and prevents unlocking and removal of the card unless the power connector is deactuated. A dielectric rail along the card's active edge is shaped to fit the channel of the power connector and protect the active edge and contact sections therealong exposed in recesses of the rail. A daughter card may have two active edges, each with a rail insertable into channels of a pair of opposed power connectors.