Overview
IEC/TS 60815-1:2008 - Selection and dimensioning of high-voltage insulators intended for use in polluted conditions (Part 1) provides definitions, information and general principles for choosing and sizing external high-voltage insulation where environmental pollution affects performance. This technical specification replaces IEC/TR 60815 (1986) and introduces a structured approach to assess site pollution severity (SPS) and to judge probable insulator behaviour in specific polluted environments.
Key topics and requirements
- Site Pollution Severity (SPS): Methods to evaluate pollution at a site, including classification schemes and recommended measurement approaches (encouraging at least one year of monitoring where possible).
- Pollutant characterization: Recognition of two solid pollution components - ESDD (equivalent salt deposit density) for soluble deposits and NSDD (non-soluble deposit density) for insoluble deposits - and the role of layer conductivity.
- Selection approaches: Three design/selection approaches are described (deterministic and statistical concepts summarized) to determine required insulator dimensions and performance.
- Creepage and geometry: Guidance on creepage distance as well as other geometric factors (profiles, length, orientation) that influence flashover risk; correction factors are introduced to account for material, size and pollution type.
- Materials and profiles: General guidance on material selection (ceramic, glass, polymeric) and insulator profiles relative to polluted conditions.
- Measurement and testing references: Normative/ informative annexes cover practical measurement and test methods - e.g., measurement of ESDD/NSDD (Annex C), directional dust deposit gauges (Annex E), laboratory test methods (Annex F), deterministic/statistical test acceptance (Annex G), and practical questionnaires and form factors (Annex H, I).
- Maintenance and mitigation: Considerations for palliative methods, maintenance intervals, and special environments (arid areas, hollow insulators, proximity effects).
Applications and users
IEC/TS 60815-1:2008 is intended for engineers and technical professionals involved in:
- Transmission and distribution utilities specifying insulators for polluted service
- Design engineers and OEMs selecting insulator dimensions and profiles
- Test laboratories and consultants conducting pollution monitoring and acceptance testing
- Asset managers planning maintenance, cleaning regimes and mitigation strategies
- Standards committees and researchers harmonizing laboratory and field severity correlations
Practical uses include selection of creepage distance and profile, interpreting field pollution measurements (ESDD/NSDD, dust gauges), defining acceptance criteria for artificial pollution tests, and preparing procurement and maintenance specifications.
Related standards
- IEC/TS 60815-2 - Ceramic and glass insulators for a.c. systems
- IEC/TS 60815-3 - Polymeric insulators for a.c. systems
- IEC/TS 60815-4 & -5 - Equivalent parts for d.c. systems
Keywords: IEC TS 60815-1:2008, high-voltage insulators, polluted conditions, site pollution severity, ESDD, NSDD, creepage distance, insulator selection, pollution monitoring.