Connecting device for transmitting electrical energy from a spatially fixed conductor rail to a tapping device which can be moved along the conductor rail or is also spatially fixed, comprising: - at least one connection housing, wherein the line rail is mechanically connected to the pick-off device via the connection housing, the connection housing comprising at least one base support on which connection components are mounted on a mounting surface, - a current pick-up device which comprises sliding contact elements for picking up electrical energy from the conductor rail, the sliding contact elements being guided through the base support and having, on a side of the base support facing away from the conductor rail, a contacting region by means of which at least one printed circuit board of the connection device and/or at least one printed circuit board of the pick-up device and/or at least one motor printed circuit board is electrically conductively contacted, wherein the connection housing has contacting shafts on a side facing the conductor rail, which contacting shafts are open at least in places in a direction parallel to the conductor rail, at least one sliding contact element running along an inner surface of each of the contacting shafts, so that an electrical line of the conductor rail, which is in each case assigned to a contacting shaft, can be contacted within the contacting shafts, and further wherein the sliding contact elements in the region of the contacting shafts are of wave-shaped design, and further wherein the contacting shafts are designed in the form of a plug-on device on the individual lines, characterised in that the connection components comprise at least one terminal and a protective circuit, and in that the protective circuit is fixed on the mounting surface of the base support. - at least one connection housing, wherein the line rail is mechanically connected to the pick-off device via the connection housing, the connection housing comprising at least one base support on which connection components are mounted on a mounting surface, - a current pick-up device which comprises sliding contact elements for picking up electrical energy from the conductor rail, the sliding contact elements being guided through the base support and having, on a side of the base support facing away from the conductor rail, a contacting region by means of which at least one printed circuit board of the connection device and/or at least one printed circuit board of the pick-up device and/or at least one motor printed circuit board is electrically conductively contacted, the connection housing has contacting shafts on a side facing the conductor rail, which contacting shafts are open at least in places in a direction parallel to the conductor rail, at least one sliding contact element running along an inner surface of each of the contacting shafts, so that an electrical line of the conductor rail, which is in each case assigned to a contacting shaft, can be contacted within the contacting shafts, and further wherein the sliding contact elements in the region of the contacting shafts are of wave-shaped design, and further wherein the contacting shafts are designed in the form of a plug-on device on the individual lines, characterised in that the connection components comprise at least one terminal and a protective circuit, and in that the protective circuit is fixed on the mounting surface of the base support.