scope:

This guide provides information on the application, operation, and coordination of high-voltage (>1000 V) fuses and associated equipment. The information supplements that presented in IEEE Std C37.48™.¹ These guidelines apply to the following specific types of equipment, intended for use on alternating current distribution and power class systems:

a) Distribution and power class current-limiting type fuses. b) Distribution and power class current-limiting fuse disconnecting switches.

c) Items a) and b) used in fuse enclosure packages.

d) Fuse supports of the type intended for use with distribution and power class fuses, and fuse disconnecting switches.

e) Disconnecting devices created by the use of a removable switch blade in a distribution or power class fuse support.

f) Distribution class and power class current-limiting, and combination types of external capacitor fuses used with a capacitor unit, groups of units, or capacitor banks.

g) Backup current-limiting fuses ("motor-starter fuses") used in conjunction with high-voltage Class E2 motor starters (see ANSI/UL 347 [B1]²).

Purpose

The purpose of this guide is to expand on aspects of the general fuse application guide, IEEE Std C37.48, in areas associated with the application and coordination of high-voltage (>1000 V) current-limiting fuses. This guide is more "tutorial" in nature than IEEE Std C37.48, and includes descriptions as to how different types of fuses work. It was developed to create a better understanding of how most fuse types operate, but with an emphasis on current-limiting fuses after the category "full-range" was added to the existing categories of "backup" and "general-purpose" current-limiting fuses.

¹ Information on references can be found in Clause 2.

² The numbers in brackets correspond to those of the bibliography in Annex B.