Underwriters’ Laboratories

Standard for Safety Enclosed and Dead-Front Switches - COMMENT DUE: APRIL 21, 2015
 N 98 BULLETIN

Annotation

These requirements cover individually enclosed air switches, rated 4000 A or less at 600 V or less, having all current-carrying parts enclosed, manually operable by means of external handles, and intended to be employed in accordance with the national installation codes listed in Annex A, Ref. No. 1.

As used in this Standard, the term switch is intended to mean an enclosed switch or deadfront switch unless specifically stated otherwise.

These requirements also cover deadfront switches that have all current-carrying parts enclosed when mounted in an enclosed panelboard, deadfront switchboard, or the like. These switches are manually operable by means of external handles and are intended to be employed in accordance with the national installation codes listed in Annex A, Ref. No. 1

These requirements cover enclosed switches with or without provision for fuses suitable for use as branch circuit, feeder, and service overcurrent protection.

The following fuses are deemed suitable for use as branch circuit, feeder, and service overcurrent protection:

a) Cartridge Fuses (Ref. Annex B, Low-Voltage Fuses – Parts 1 – 10, 12 and 15),

b) Plug Fuses (Ref. Annex B, Low-Voltage Fuses – Parts 1 and 11), and

c) Special Purposes Fuses marked as meeting the performance specifications of a specific Class Fuse.

These requirements cover enclosed switches intended for general use and having ampere ratings, with or without horsepower or kilowatt ratings, and enclosed switches intended for motor-circuit use only and having horsepower or kilowatt ratings but no general-use ampere ratings.