The importance of knowing available fault currents when specifying interrupting ratings for low-voltage equipment

In a number of industrial plants, personnel responsible for the maintenance and design of the electrical power systems have done an excellent job at sizing equipment for connected loads; however, on more than one occasion, those same personnel appeared to be unaware of the interrupting rating for low voltage equipment. This sometimes resulted in electrical power systems that posed hazards to personnel and equipment due to the incorrect application of protective equipment. Several aspects of proper equipment selection based on interrupting ratings are addressed by the author.