Electricity metering equipment (AC) - General requirements, tests and test conditions -- Part 21: Tariff and load control equipment (IEC 62052-21:2004 + A1:2016) (english version)
91.140.50 Electricity. Including electric energy meters in buildings, emergency electrical supplies, etc. / Системы электроснабжения. Включая аварийное электроснабжение и т.д.
