Apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling electricity; electrical and electronic components; electronic components; connecting elements for cables and wires and parts therefor, in particular connectors and pin and socket connectors and parts therefor; wiring systems, namely, mounting plates, relay plates and card frames with electric connections; electrical switch cabinets and distribution boxes (electricity); electric distributor housings; components, in relation to the following goods, electrical switch cabinets, distribution boxes (electricity), electric distributor housings; accessories, in relation to the following goods, electrical switch cabinets, distribution boxes (electricity), electric distributor housings; cable channels (electric); specially adapted fastening elements, support rails, lifting rails, mounting bars and mounting frames for fastening and holding, in relation to the following goods, power modules, electronic modules, module housing, electrical cabling, electric cords, in particular electrical switch cabinets