In addition to the general requirements of IEC 60077-2, this international standard gives rules for a.c. circuit-breakers, the main contacts of which are to be connected to a.c. overhead contact lines; the nominal voltage of these circuits being in accordance with IEC 60850. This standard, together with IEC 60077-2, states specifically: a) the characteristics of the circuit-breakers; b) the service conditions with which circuit-breakers have to comply with reference to: operation and behaviour in normal service; operation and behaviour in short-service; dielectric properties; c) the tests for confirming the compliance of the components with the characteristics under the service conditions and the methods to be adopted for these tests; d) the information to be marked on, or given with the circuit-breaker. NOTE 1 Circuit-breakers which are dealt with in this standard may be provided with devices for automatic opening under pre-determined conditions other than those of over-current, for example, undervoltage and reversal of power current. This standard does not deal with the verification of operation under such predetermined conditions. NOTE 2 The incorporation of electronic components or electronic sub-assemblies into electrotechnical components is now common practice. Although this standard is not applicable to electronic equipment, the presence of electronic components does not provide a reason to exclude such electrotechnical components from the scope.