IS 4248 : 1967 Non-ignitable and self-extinguishing boards (with mineral base) for electrical purposes

1 Scope

1.1 This standard covers the requirements of four classes ofnon-ignitable boards and self-extinguishing boards for electrical purposes.

2 References

IS 2 :1960 Rules for rounding off numerical values

IS 335 : 1963Specification for insulating oil for transformers and switchgear

IS 1876 : 1961 Methodfor voltage measurement by means of sphere gaps(one sphere earthed)

IS 2584 : 1963Methods of test for electric strength of solid insulating materials at power frequencies

IS 4249 : 1967Classification and methods of test for the non-ignitableand self-extinguishing properties of solid electrical insulating materials