General Selection Criteria

Selection of inter-teknik HV fuses shall be based on fuse data and recommendations as given in this web page and other applicable inter-teknik literature.

Fuse selection shall follow these general rules:

  • The rated current shall be selected significantly higher than the operating current, at least about twice the equipment operating current.
  • Transient currents associated with switching of transformers, motors or capacitors shall be carried without premature operation or deterioration of fuse-elements.
  • The range of expected fault currents must be between the minimum and the maximum breaking currents of the fuse-link.
  • If the rated voltage of the fuse is significantly higher than the max. rated voltage of the system, it should be noted that the switching voltage of the fuses must not exceed the system insulation voltage in order to avoid insulation damage or surge arrester failure. Selection of higher voltage ratings is limited by the insulation voltage of the system.
  • Co- ordination with other protective devices may be applicable.


Protection of associated equipment and coordination with other devices, such as switch-fuse combinations, require additional criteria to take into consideration.

Please follow the links related to your application for more details.

Related Links:

Selection table for transformers
Selection tables for motors
Switch-Fuse combinations
Capacitor Banks
Voltage Transformers
Catalogues-Flyers