IS 11697 : 1986 Guide for determination of lightning impulse electric strength of insulating liquids

1 Scope

1.1 This guide describes test methods for assessing the electricstrength of insulating liquids when subjected to standard lightningimpulse in a divergent field.

1.1.1 Two methods are suggested:

a) Method A is based on a step-by-step procedure to provide anestimate of the impulse breakdown voltage under specifiedconditions; and

b) Method B is a statistically designed test to checkstatistical hypothesis about the impulse breakdown probability ofan insulating liquid at a given voltage level.

2 References

IS 2 :1960Rules for rounding off numerical values

IS 1876 :1961Method for voltage measurement by means ofsphere-gaps (one sphere earthed)

IS 2071 : Part 2 :1976 Methods of high voltage testing:Part 2 Test procedures

IS 2071 : Part 3 :1976 Methods of high voltage testing:Part 3 Measuring devices

IS 8090 :1976Specification for coupling, branch pipe, nozzleused in hose reel tubing for fire fighting

IS 9434 :1979Guide for sampling and analysis of free anddissolved gases and oil from oil-filledelectrical equipment