MT 19 - TC 36/MT 19

IEC TS 62896:2015(E) applies to hybrid insulators for a.c. and d.c. applications consisting of a load-bearing insulating solid or hollow core consisting of ceramic or glass, a housing (defined geometry, outside the insulating core) made of polymeric material and end fittings permanently attached to the insulating core. Hybrid insulators covered by this technical specification are intended for use as suspension/tension line insulators, line post insulators, station post insulators and hollow core insulators for apparatus. The object of this technical specification is to:
- define the terms used;
- prescribe test methods;
- prescribe acceptance criteria.
Silicone or other functional coatings (CIGRE Technical Brochure No. 478, Appendix B), booster sheds, shed extenders and rain deflectors are not within the scope of this technical specification. This technical specification does not include requirements dealing with the choice of insulators for specific operating conditions.

IEC 62217:2012 is applicable to polymeric insulators whose insulating body consists of one or various organic materials. Polymeric insulators covered by this standard include both solid core and hollow insulators. They are intended for use on HV overhead lines and in indoor and outdoor equipment. The object of this standard is:
- to define the common terms used for polymeric insulators;
- to prescribe common test methods for design tests on polymeric insulators;
- to prescribe acceptance or failure criteria, if applicable.
These tests, criteria and recommendations are intended to ensure a satisfactory life-time under normal operating and environmental conditions. This standard shall only be applied in conjunction with the relevant product standard. This second edition cancels and replaces the first edition published in 2005. This edition constitutes a technical revision. This edition includes a significant technical change with respect to the previous edition. The first edition of IEC 62217 (2005) included two other alternative tracking and erosion tests (a 5 000 hour multi-stress test and a tracking wheel test) which were based on tests developed by CIGRE and utilities. These tests are no longer given as normative alternatives following the results of a study/questionnaire by TC 36 on the relative merits of all three tracking and erosion tests. The 5 000 hour multi-stress test and a tracking wheel test are described in IEC/TR 62730 (2012).

IEC/TR 62730:2012(E) is applicable to polymeric insulators whose insulating body consists of one or various organic materials. Polymeric insulators covered by this technical report include both solid core and hollow insulators. They are intended for use on overhead lines and in indoor and outdoor equipment with a rated voltage greater than 1 000 V. The object of this technical report is:
- to define the common terms used;
- to give the background behind the development and use of the 5 000 h multiple stress test and the tracking wheel test;
- to describe the test methods for the 5 000 h multiple stress test and the tracking wheel tests on polymeric insulators;
- to describe possible acceptance or failure criteria, if applicable. Key words: polymeric insulators, multiple stress test, 5000 h

IEC/TR 62662:2010(E) presents an analysis of the risk of influencing factors for brittle fracture of composite insulators that are mostly loaded in the tensile mode (suspension and tension insulators). Guidance is given to reduce the risk of in-service brittle fractures.