AS IEC 62217:2021 – Polymeric HV insulators for indoor and outdoor use -General definitions, test methods and acceptance criteria.
part of the fixing device which transmits load to the hardware external to the insulator
process which forms irreversible degradation by formation of conductive paths (tracks) starting and developing on the surface of an insulating material,
Note I to entry: Tracking paths are conductive even under dry COfldiIiOfls.
Irreversible and non-conducting degradation of the surface of the insulator that occurs by loss of material. This can be uniform, localized or tree-shaped
Note I to entry: Light surtace traces, commonly tree-shaped, can occur on composite insulators as on ceramic insulators, aft.r partial flashov.r Th.s. traces are not considered to be oe.ctionabie as long as they ace non• conductive. When they are conductive they are ClaSsified as tracking.
any internal fracture or surface fissure of depth greater than 0.1 mm
permanent loss of dielectric strength due to a disruptive discharge passing through the solid Insulating material of an Insulator
ISOURCE: IEC 60050-471:2007, 471-01-14, modified to define puncture as the result of a discharge, rather than the discharge itselfj
4 ldentlfkation
The manufacturer’s drawing shall show the relevant dimensions and information necessary for identifying and testing the insulator in accordance with this International Standard and the applicable IEC product standard(s). The drawing shall also show applicable manufacturing tolerances.
Each insulator shall be marked with the name or trademark of the manufacturer and the year of manufacture. In addition, each Insulator shall be marked with the rated characteristics specified In the relevant IEC product standards. These marlungs shall be legible, Indelible and their fixings (if any) weather- and corrosion-proof.
5 Environmental conditions
The normal environmental conditions to which insulators are submitted in service are defined according to Table 1.
When special environmental conditions prevail at the location where insulators are to be put in service, they shall be specified by the user by reference to IEC 60721-1.
7.2 Type tests
The type tests are intended to verify the main characteristics of a polymeric insulator, which depend mainly on its shape and size. Type tests shall be applied to polymeric insulators belonging to an already qualified design class. The type tests shall be repeated only when the type of the polymeric insulator is changed. The parameters defining a type of polymeric insulator are given in the relevant product standard.
The applicable type tests are given in the relevant product standard.
7.3 Sample tests
The sample tests are intended to verify the characteristics of polymeric insulators which depend on the quality of manufacture and on the materials used. They are made on insulators taken at random from lots offered for acceptance.
The applicable sample tests are given In the relevant product standard
7.4 Routine tests
These tests are intended to eliminate polymeric insulators with manufacturing defects. They are carried out on every insulator to be supplied.
The applicable routine tests are given In the relevant product standard.
8 General requirements for insulator test specimens
Insulator test specimens for tests of polymeric insulators shall be checked prior to tests:
• for correct assembly, for example by applying the mechanical routine test specified in the relevant product standard,
• by visual examination according to the relevant product standard;
• for conformance of dimensions with the actual drawing.
For dimensions a without tolerances the following tolerances are acceptable:
• i(O,O4d+1.5)mm whend.3OOmm.
• ± (0,025 d + 8) mm when d> 300 mm with a maximum tolerance of ±50 mm.
The measurement of creepage distances shall be related to the design dimensions and tolerances as determined from the insulator drawing, even if this dimension is greater than the value originally specified. When a minimum creepage Is specified, the negative tolerance is also limited by this value.
In the case of insulators with creepage distance exceeding 3 m. it is allowed to measure a short section around 1 m long of the insulator and to extrapolate.