NDB3-30, 50, 100 series circuit breakers for equipment (hydraulic electromagnetic type) are applicable to electric systems with the rated current of 100A and the rated voltage not higher than AC480/277V (50/60Hz) and DC125V. The products can be used for infrequent making and breaking as well as overload and short-circuit protection. They are widely used in the computer and peripheral equipment, industrial automation system, telecommunication equipment, universal power supply system, UPS equipment, locomotive, marine electrical system, aerospace, elevator control system and mobile power supply equipment.