IS 9431 : 1979 Indoor post insulators of organic material for systems with nominal voltages greater than 1 000 V up to and including 300 kV

1 Scope

1.1 This standard covers the requirements of post insulators oforganic material for indoor service in electrical installations orequipment operating in air at atmospheric pressure on alternatingcurrent with a rated voltage greater than 1 000 V up to andincluding 300 kV and a frequency not greater than 100 Hz.

Note - The post insulators covered by this standard areprimarily intended for use in disconnectors or circuit breakers, oras bus-bar or fuse supports.

2 References

IS 2 :1960Rules for rounding off numerical values

IS 196 :1966Specification for atmospheric conditions fortesting

IS 2544 :1973Specification for porcelain post insulators forsystems with nominal voltages greater than1 000 volts

IS 2071 : Part I :1974 Methods of high voltage testing:Part I General definitions and test requirements

IS 2071 : Part II :1976 Methods of high voltage testing:Part II Test procedures

IS 5350 : Part I :1970 Dimensions of indoor and outdoorporcelain postinsulators and post insulator units for systemwith nominal voltages greater than 1 000 V:Part I Indoor post insulators

IS 6209 :1971Methods for partical discharge measurements