Connection system comprising a coupling device and a plug element for a welding torch connected to at least one hose assembly, said coupling device arranged at least partially in a housing, wherein a first medium comprising a welding wire, delivered by a feed unit which is arranged on a motor plate, and additional media are conducted to the welding torch via the hose assembly and wherein the hose assembly is connected to the plug element, wherein the coupling device is formed by a connection device comprising an end wall and a separation wall of the motor plate, wherein the end wall is designed to receive a coupling, wherein the connection device is constructed to at least guide and position a pin, wherein the connection device is independent of the housing, and wherein an electrical coupling of the coupling device is arranged between the end wall and the separating wall, wherein the electrical coupling is equipped with a feed through and an interlocking system for a pin, wherein the feed through is designed to be a connection for transmitting the welding current to the pin and wherein the interlocking system has a lever, and wherein the lever changes the diameter of the feed through by exerting eccentric power and secures the pin.