Abstract: A safety receptacle or contact system for use at the outlet end of an electric supply line and for connection of at least one attachment plug that has at least two contact pins; the receptacle comprises a base plate; at least two connector ends supported by the base plate; a lid or cover housing including a front plate having at least two openings for receiving the plug pins and for guiding them into contact with the connector ends; an electrical circuit associated with the receptacle for controlled connection of the connector ends with the electric supply line and comprising a relay for breaking contact between the connector ends and the supply line when the two plug pins are withdrawn from the receptacle; and a light barrier connected with the relay for control thereof and arranged for operation in response to connection or non-connection of the plug with the receptacle.