91.140.50 Electricity. Including electric energy meters in buildings, emergency electrical supplies, etc. / Системы электроснабжения. Включая аварийное электроснабжение и т.д.
Applicable to newly manufactured induction type var-hour meters for the measurement of reactive energy of frequency between 40 Hz and 60 Hz, of an accuracy class of 3.0 for ordinary usage, and to their type tests.