Exemplary embodiments are directed to a plug-in system having a lower part, on which busbars can be arranged, and an upper part which is made of electrically insulating material and is releasable from the lower part in a non-destructive manner on a top side arranged opposite the underside. Protective devices having electrical contacts can be arranged on the plug-in system. The upper part has openings through which the electrical contacts of the protective devices can make direct contact with the busbars. The openings are configured in such a manner that the plug-in system is shockproof to IP XXB. The upper part and lower part are latchable into one another or are screwable to one another in such a manner that the upper part is releasable from the lower part only from the underside of the plug-in system.