HD 309.1 S1:1979

Class 2 direct connected alternating-current watthour meters - Part I

Scope

This standard applies only to newly manufactured induction type watthour meters of accuracy classes 0.5, 1 and 2, for the measurement of alternating-current electrical active energy of a frequency in the range 45 Hz to 65 Hz and it applies to their type tests only - It applies to the assembly of meters and accessories including current transformers when enclosed in the meter case - It does not apply to maximum demand indicators (see IEC Publication 211 Maximum Demand Indicators Class 1.0) - It does not apply to any kind of measuring device such as those used for telemetering electrical energy - It does not apply to meters for testing purposes or to special types of watthour meters (e.g. excess meters) except for multi-rate meters - It does not apply to watthour meters where the voltage across the connection terminals exceeds 600 V (line-to-line voltage for meters for three-phase systems) * Note 1: For portable meters and meters for outdoor, using additional requirements may be necessary * Note 2: For var-hour meters, see IEC Publication 145: Var-hour (reactive Energy) Meters