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LV HRC fuses


LV HRC fuses are used for installation systems in non-residential, commercial and industrial buildings as well as in the switchboards of power supply companies.
Fuses protect cables and wiring from overloading and shortcircuit currents.
In addition to this, they are suitable for protecting equipment and devices. They, for example, protect:

  • motors in case of transient operational overloading
  • and provide protection against occassionally occurring shortcircuits.
They protect human beings in fault conditions against inadmissible touch voltages in TN and TT networks.
They provide back-up protection for miniature circuit-breakers and residual-current operated circuit-breakers.
The high degree of selectivity guarantees optimum protection in radial and meshed networks.

LV HRC fuse-links

LV HRC fuse-links (SOURCE: Siemens)

Utilization categories

The utilization categories of low-voltage fuses are defined in the IEC 60269 standard. Utilization category gG is defined for cable and conductor protection.
According to DIN VDE 0636, the previous designation for cable and line protection was gL, whereas gG is presently valid.
The utilization category aM for switchgear protection in the shortcircuit range is defined equally according to IEC 60269 and DIN VDE 0636.