DIN EN 62054-21:2017-10

This part of IEC 62054 specifies particular requirements for the type test of newly manufactured indoor time switches with operation reserve that are used to control electrical loads, multi-tariff registers and maximum demand devices of electricity metering equipment. The time switch keeps the real time, it may keep the date, it may be capable of handling leap years, it may support daylight saving; that is, it modifies the deviation of local time to GMT according to the relevant regulations. The time switch may have a synchronization capability. The time switch also holds a schedule of switching actions, which may be specified in terms of time, day of the week, date within a month or a year. The time switch controls the output elements depending on the time and the schedule of switching actions stored. This standard gives no requirements for constructional details internal to the time switch. The responsible committee is DKE/K 461 "Messeinrichtungen und -systeme für Elektrizität" ("Metering equipment and systems for electricity") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.