A plug adapter for plugging a connecting lead having at least two poles onto a switching device having a respective secondary contact, for a respective lead conductor, disposed parallel to a combination plug-in orifice includes, on a bottom side facing the switching device, a housing cutout. Associated with each of the at least two poles is a respective access contact including a contact spring. The access contact has a housing opening, and a respective plug, a respective conductor bar. The free end of the contact spring is elastically preloaded, and a clamping device is configured to simultaneously clamp the lead conductors to the contact spring and actuatable via an actuator bracket.