DIN CLC/TR 62662:2017-01

This technical report 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. This phenomenon is limited to tension and suspension insulators. However, the general information given concerning the importance of various parameters can be used as a guideline for the design and production of any kind of composite insulator. Acid resistance (brittle fracture) of GFRP core materials has been identified as an important property for suspension and guyed composite insulators. This technical report, considering different insulator designs and production techniques, provides even more detailed guidelines on this subject. The risk of occurrence and the influencing variables were evaluated by failure mode and effects analysis (FMEA). Brittle fracture is not the only failure mechanism for insulators in service and is generally observed less frequently than other types, such as failure due to tracking and erosion. However, this issue has not yet been covered by an IEC test method that can be used to prevent brittle fracture in particular. The responsible committee is DKE/K 451 "Isolatoren" ("Insulators") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.