|Generation, Distribution, Use of Electric Current - Basic vocational knowledge (Institut für Berufliche Entwicklung, 141 p.)|
Electric current is generated, distributed and used in a closed system, normally called electrical installation (or plant). Physical effects make it necessary to subdivide the electrical installation into two subsystems:
Power unit (or electric energy equipment)
It is exclusively used for the generation, transformation, storage, transmission, distribution and use of electric energy and comprises an energy unit with the equipment to serve the afore-mentioned purpose and an information unit to guarantee the control and protection of the installation.
Secondary unit (or information equipment)
It is used for the generation, acquisition, transmission, processing and output of information (control and protection of the electrical installation) and comprises an energy unit to supply the necessary energy and an information unit with the respective equipment to serve the afore-mentioned purpose of the installation.