The final stage of compliance verification focuses on the current-carrying conductor itself and its interface with the broader electrical system via terminations. Proper conductor sizing is essential to ensure both thermal and electrical integrity under all specified load conditions. Similarly, correct termination design is paramount for guaranteeing the safety and long-term reliability of connection points.

6.1 Conductor Size Selection

In accordance with Clause 5 of the standard, the selection of the conductor size must be verified against the following three primary factors, with the evaluation documented for compliance:

• Maximum Temperature: Verification that the conductor’s cross-sectional area is adequate for the specified continuous load, cyclic load, or emergency load conditions without exceeding the cable’s maximum permissible operating temperature.
• Mechanical Loads: Assessment of any mechanical stresses that may be imposed on the conductor during the installation process and throughout its service life.
• Electrical Stress: Confirmation that the conductor’s cross-sectional area is sufficient to prevent unacceptably high electrical stress within the insulation material.

6.2 Termination Requirements

The insulation levels for terminations against power-frequency and impulse voltages must be selected based on the system fault category (Clause 4) and the specific environmental factors at the installation site. The design and selection of cable terminations must account for these conditions. Based on Clause 6, the following factors must be considered and verified:

• Atmospheric Pollution: The documented degree of environmental pollution at the termination site determines the minimum required creepage distances and the appropriate type of insulators for the cable sealing ends.
• Altitude: For installations at altitudes above 1000 m, verification is required to confirm that air clearances have been increased by a suitable amount. This is necessary to compensate for the lower electric strength of air at higher altitudes.

These final checks on the conductor and its terminations complete the core verification process against the standard.