Overview
IEC/TS 60815-2:2008 - Selection and dimensioning of high-voltage insulators intended for use in polluted conditions - Part 2: Ceramic and glass insulators for a.c. systems provides practical guidance for choosing and sizing porcelain and glass insulators used on high‑voltage a.c. systems exposed to pollution. This Technical Specification complements IEC/TS 60815-1 and replaces the earlier IEC/TR 60815 (1986). It helps translate site pollution information into concrete insulator creepage and profile requirements and recommends verification tests.
Key topics and requirements
- Reference unified specific creepage distance (RUSCD): Methods to determine RUSCD from the site pollution severity (SPS) class, expressed in mm/kV.
- Unified specific creepage distance (USCD): Definition and role of USCD as creepage distance divided by the r.m.s. highest operating voltage.
- Profile evaluation and selection: Guidance on suitability of different shed/profile types (standard, open, anti‑fog, alternating, pin sheds) and their advantages/disadvantages.
- Profile parameter checks: Criteria for shed overhang, spacing, minimum distance between sheds, shed angle, creepage factor and interaction between creepage and clearance.
- Corrections to RUSCD: Adjustment factors for insulator altitude, diameter, shape, mounting position and other physical parameters.
- Confirmation by testing: Recommended verification procedures including long‑duration withstand voltage, selection of pollution withstand test types, artificial pollution test parameters and pass/fail criteria.
- Materials scope: Applicable to standard ceramic (porcelain) and glass insulators (excluding surface‑treated variants unless otherwise noted).
Practical applications
- Specifying insulators for overhead lines, substations, bushings and post‑insulators in polluted coastal, industrial or desert environments.
- Converting site pollution surveys (SPS, ESDD/NSDD) into minimum creepage and profile requirements to reduce flashover risk.
- Evaluating alternative insulator profiles and scaling dimensions for existing designs.
- Defining laboratory artificial pollution tests (IEC 60507 referenced) to confirm field performance.
Who should use this standard
- Transmission and distribution utilities and network planners
- Substation and line design engineers
- Insulator manufacturers and product engineers
- Test laboratories and qualification teams
- Consultants involved in environmental assessment and asset selection
Related standards
- IEC/TS 60815-1 - Definitions, information and general principles (companion document)
- IEC 60507 - Artificial pollution tests on high‑voltage insulators to be used on a.c. systems
- IEC 60050-471 - Vocabulary: Insulators
Keywords: IEC TS 60815-2:2008, high-voltage insulators, polluted conditions, ceramic insulators, glass insulators, creepage distance, RUSCD, USCD, site pollution severity, artificial pollution test.