You cannot simply use the baseline USCD value. Glass and ceramic insulators come in various profiles (e.g., standard, anti-fog, aerodynamic). IEC 60815-2 forces engineers to apply correction factors based on the specific shape parameters of the chosen shed. Key Geometric Profiles Evaluated: Shed Spacing (
Part 2 is for ceramic/glass only. For polymeric (silicone, EPDM) insulators, you must use IEC 60815-3 . Polymeric materials have hydrophobicity, which temporarily reduces pollution severity, allowing lower creepage.
Areas with low-density housing or light industry, sheltered from marine winds. iec 60815-2 pdf
The standard gives structured guidelines to help engineers:
is the international standard used to select and size ceramic and glass insulators for high-voltage systems in polluted environments. Pollution on insulators causes dry-band arcing, which leads to flashovers and widespread power outages. You cannot simply use the baseline USCD value
If you are working on a specific design project, please let me know:
The primary goal of the specification is to give engineers a methodology to: Key Geometric Profiles Evaluated: Shed Spacing ( Part
Designing an insulator using IEC 60815-2 involves a structured, step-by-step approach that evaluates the environment before sizing the equipment. 1. Site Pollution Severity (SPS) Evaluation
: Define laboratory test parameters and criteria to confirm that a selected insulator will perform reliably in the field. IEC TS 60815-2:2008
A common 146 mm/kV cap-and-pin unit has a creepage of ~320 mm. Number of units needed = 5510 / 320 = 17.2 → 18 units . A typical clean-air 132 kV string might use only 9-10 units. Pollution doubles the requirement.