Arc flash incidents on faulted, industrial equipment cause injuries and deaths in the workplace each year, despite awareness of and compliance with safety rules. Fused switches and fused circuit breakers have typically provided arc flash protection. Today, however, the breakthrough technology of the Masterpact NW and NT circuit breaker represents an effective arc flash solution - without the use of, and problems associated with, fuses.

Designed to interrupt large fault currents without fuses, Masterpact NW and NT circuit breakers clear faults very quickly and provide comparable arc flash protection to fuses at high currents and better arc flash protection at lower currents. Plus, they eliminate problems common to fused switches and fused circuit breakers, including:

• Hazards associated with changing fuses
• Required maintenance for mechanical hardware and wear items including the fuse holder, blown fuse indicators and single phasing devices
• Higher energy costs due to additional resistances in the fuse holder and connections
• Larger equipment size
• Higher installation and service life costs

Benefits

• Comparable or better arc flash incident energy and personnal protection to fuse protected circuit breakers
• Reliable power
• Adjustability for coordination and continuity of service
• Smaller footprint
• Reduced maintenance needs
• High interrupting ratings without fuses: Masterpact NW =
  200,000 A at 508 VAC
• Circuit breakers designed for all applications:
  • High withstand-rated circuit breakers for system coordination
  • High close and latch ratings for systems with high inrushes, etc.
  • Quick-opening designs for high available fault currents
  • Quick-opening designs for arc flash protection without fuses