DIN EN 62271-105:2013-08

This standard applies to three-pole alternating current switchgear for public and industrial distribution systems which are functional assemblies of switches including switch-disconnectors and current-limiting fuses and are capable of breaking, at the rated recovery voltage, any current up to and including the rated short-circuit breaking current and making, at the rated voltage, circuits to which the rated short-circuit breaking current applies. It applies to combinations designed with rated voltages above 1 kV up to and including 52 kV for use on three-phase alternating current systems of either 50 Hz or 60 Hz. This standard does not apply to fuse-breaker-circuit breaker combinations, fuse-contactor combinations, combinations for motor-circuits or to combinations incorporating single capacitor bank switches. The fuses are incorporated in order to extend the short-circuit breaking rating of the combination beyond that of the switch alone. They are fitted with strikers in order both to open automatically all three poles of the switch on the operation of a fuse and to achieve a correct operation at values of fault current above the minimum melting current but below the minimum breaking current of the fuses. In addition to the fuse strikers, the combination may be fitted with either an over-current release or a shunt release. The following modifications have been made with respect to the previous standard DIN EN 62271-105 (VDE 0671-105):2003-12: a) arrangement of the figures to the place where they are cited first; b) renumbering of tables; c) addition of some of the proposals from IEC paper 17A/852/INF; d) addition of missing clauses corresponding with EN 62271-1; e) arrangement of 6.105 "Extension of validity of type tests" and consequently removing the relevant parts in the different existing clauses; f) modification of the 7th paragraph of 6.101.4 as there is now a definition of NSDD given in 3.7.4 of EN 62271-1:2008. Harmonization with EN 62271-107; g) some referenced clauses in other standards like EN 60282-1 were changed and therefore the normative references in 1.2 were updated; h) addition of a new Annex C specifying tolerances. The responsible committee is UK 432.1 "Hochspannung-Schaltgeräte" ("High-voltage switchgear") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.