In this book, the processes that determine the waveforms and magnitudes of short-circuit currents are described. The deviation of the formulae required for calculation in the short-circuit categories indicated in the VDE 0102 recommendations is explained with the aid of symmetrical components. The relationships that enable the system impedances to be determined from the parameters of the components of the system, and the resulting short-circuit impedance of the network, are adduced. Some representative examples demonstrate the practical application of short-circuit calculations. Typical characteristic data for system components are presented in curves and in tables. The book concludes with a reference to the use of digital simulation methods in short-circuit studies.