Cable terminations are a critical system component, acting as the interface between the cable and other equipment. Their design is highly dependent on the specific environmental conditions at the point of termination, which can differ significantly from the conditions along the cable’s primary route. Specifying terminations correctly is essential to ensure they do not become a weak point in the high-voltage system, as noted in Clause 6 of the standard.

The following key environmental factors must be analyzed to ensure a robust termination design:

• Atmospheric Pollution: The degree of exposure to industrial or environmental pollution is a primary determinant of termination design. This factor dictates the minimum required creepage distances along the insulator surface and influences the type of insulators to be used for the cable sealing ends to prevent flashover.
  • Practical Insight: In heavily polluted or coastal saline environments, specifying insufficient creepage distance is a leading cause of termination failure. Always select a pollution level category that accounts for the worst-case environmental conditions, not the average.
• Altitude: At high altitudes (defined as above 1000 m), the reduced air density lowers its natural electric strength. This means that standard air clearances, which are adequate at sea level, may be insufficient. To ensure proper insulation and prevent flashover at high altitudes, the air clearances for the termination must be increased by a suitable amount.

By following this structured and methodical approach based on the guidance in IEC 183, from voltage definition to termination design, professionals can develop a comprehensive and robust specification that ensures the selection of a safe, reliable, and appropriate high-voltage cable for any project.