IEC 60112:2003 ED4

Method for the determination of the proof and the comparative tracking indices of solid insulating materials

Scope

Specifies the method of test for the determination of the proof and comparative tracking indices of solid insulating materials on pieces taken from parts of equipment and on plaques of material using alternating voltages. The standard provides for the determination of erosion when required. Test results cannot be used directly for the evaluation of safe creepage distances when designing electrical apparatus. Major changes since the previous edition are the following: The selection of a material for a specific application frequently involves compromises in the levels of the individual properties and test criteria. In the previous edition of IEC 60112 the test criteria required "no burning of the specimen", but this gave rise to two issues:
- difficulties in the identification of burning which includes all types of combustion, e.g. flaming, and smouldering in the situation where scintillations had occurred giving rise in many cases to carbon on the surface of the specimen, and
- a situation in which some product committees had found it necessary to dispense with the "no burning" criterion in the tracking tests which they replaced by flame tests on the final product, thereby giving rise to two types of CTI/PTI with different criteria.
The contents of the corrigenda of June 2003 and October 2003 have been included in this copy.