IS 731 : 1971 Porcelain insulators for overhead power lines with a nominal voltage greater than 1000 V

1 Scope

1.1 This standard applies to the porcelain insulators for acoverhead power lines suitable for nominal system voltage greaterthan 1000 volts and a frequency not greater than 100 Hz.

Note 1 - The specification applies to string insulator units, toinsulator strings consisting of one-string insulator unit or anassembly of such units, and to rigid over head line insulators. Thespecification applies to insulators of the same type when used insub-stations. It dots not apply to insulators forming part ofelectrical apparatus or to parts used in their conduction.

Note 2 - This specification applies to insulators for use on acoverhead lines

2 References

IS 2 :1960Rules for rounding off numerical values

IS 196 :1966Atmospheric conditions for testing

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

IS 2071 : Part II :1974 Methods of high voltage testing:Part II Test procedures

IS 2486 : Part I :1971 Specification for insulator fittingsforoverhead power lines of 3.3 kV and above:Part I General requirements and tests

IS 2486 : Part II :1974 Specification for insulator fittings foroverhead power liner of 3.3 kV and above:Part II Dimensional requirements

IS 2633 :1972Methods of testing uniformity of coating onzinc coated articles

IS 5621 :1970Specification for large hollow porcelains foruse in electrical installation