HRC FUSES - MAJOR DESIGN COMPONENTS FOR LOW VOLTAGE DISTRIBUTION SYSTEMS

摘要

On the basis of standardized fuse-links, specifically designed fuse-bases and -where applicable- fuse-carriers may offer a variety of additional functions to the installer and operator of LV distribution systems, e. g.rncompact sized and clearly arranged distribution panels,rnless assembly effort,rnuniform components,rnadaptability to load circuits,rnsectionalizing and isolating function,rnload-break function.rnBy means of the example of specific design features of the NH system according to IEC Publ. 269-2-1 Section I "Fuses with Blade Contacts", the authors explain some of the useful additional features fuses may exhibit in LV distribution systems. Triple fuse-bases for installation on copper busbars of a 3-phase system (fuse-rails) have shown to be very efficient in space consumption, installation effort and clearness of the arrangement of distribution panels.rnThe generally high breaking capacity of NH fuse-links enables side-by-side installation of low and high rated current circuits on high-power busbar systems. As NH fuse-links are interchangeable by rated current, rated voltage and utilization category the distribution panels are very flexible in use even after installation. Increasing load or changing equipment, in most cases requires the replacement of fuse-links only and no modification of the panel.rnThe nature of NH blade-contacts made of solid copper or brass allows for load-break operations. Clear operating instructions for work with NH fuses allow for a high level of workers' safety. With the fuse-links removed, the fuse-base represents an easily visible isolating distance between adjacent parts of the network. Thus NH fuse-panels offer a great number of possibilities to sectionalize a LV network at reasonable costs. Power interruptions caused by faults or maintenance work may thus be limited to small areas and the continuity and reliability of service increased in an economic way.