IEC 60687:1980

Applies to newly manufactured static watt-hour meters of accuracy classes 0,2 S and 0,5 S, for the measurement of alternating-current electrical active energy of a frequency in the range 45 Hz to 65 Hz and to their type tests only. This standard applies only to transformer-operated meters for indoor application consisting of a measuring element and register(s) enclosed together in a meter case. Their measuring range and rated current (In) are therefore in accordance with IEC 60185. Applies to operation indicator(s), test output(s) and meters which measure energy in both directions.