IS 722 Pt.9-1972

标准号：IS 722 Pt.9-1972
发布日期：1972/11/1 12:00:00
实施日期：1999/12/31 12:00:00
适用范围：1.1 This standard ( Part IX) applies to the following types of watthour meters of an accuracy class 1·0:a) Whole-current and transformer-operated watthour meters for unbalanced load for use in 3-phase 3-wire and 3-phase 4-wire supplies, andb) Transformer-operated watthour meters for use in single-phase 2-wire supplies.1.2 It does not apply to:a) three-phase whole-current and transformer-operated meters, and single-phase 2-wire transformer-operated meters which are covered by IS : 722 ( Part III) - 1966*;b) single-phase whole-current meters which are covered by IS : 722 (Part II/Sec 1 ) - 1962〓 or IS : 722 ( Part II/Sec 2 ) - 1969〓;c) meters for reactive or apparent energy; andd) meters having a maximum demand indicator or other auxiliary device, except contacting devices and reverse running stops.1.3 This part also does not apply to meters in which the principle of measurement requires balanced conditions of load or supply.