IEEE Cable Termination Levels by Class

IEEE termination levels are the levels of electrical safety and quality set by the Institute of Electrical and Electronics Engineers (IEEE) for the proper termination of conductors in power systems. These standards are designed to ensure safe and reliable operation of power cable connections.

IEEE Standard 48-2020 provides test procedures and requirements for all indoor and outdoor cable terminations used on alternating-current shielded cables having laminated insulation rated 2.5 kV through 765 kV and extruded insulation rated 2.5 kV through 500 kV, except separable insulated connectors, which are covered by IEEE standard 386-2006.

Cable terminations and component parts are described by class and should be able to withstand the tests specified in this standard.

Class 1 Termination

Provides electric stress control for the cable insulation shield terminus; provides complete external leakage insulation between the cable conductor(s) and ground; and provides a seal to the end of the cable against the entrance of the external environment and maintains the operating design pressure, if any, of the cable system. This class is divided into three types:

  • Class 1A: For use on extruded dielectric cable
  • Class 1B: For use on laminated dielectric cable
  • Class 1C: Expressly for pressure-type cable systems

Class 2 Termination

Provides electric stress control for the cable insulation shield terminus, and provides complete external leakage insulation between the cable conductor(s) and ground.

Class 3 Termination

Provides electric stress control for the cable insulation shield terminus.

Indoor Termination–Dry

A termination intended for use where it is protected from solar radiation and precipitation and not subject to periodic condensation, or other excessive humidity (90% RH or more). May be installed in air conditioned or heated areas.

Indoor Termination–Wet

A termination intended for use where it is protected from direct exposure to both solar radiation and precipitation, but is subjected to climatic conditions that can cause condensation onto the termination surfaces.

Outdoor Termination

A termination intended for use where it is not protected from direct exposure to either solar radiation or precipitation. These are Class 1A, 1B, or 1C terminations. Class 2 terminations may also qualify.