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Breakmaster V MV LIS

For facilities that are concerned with Arc Flash Safety Standards, the options may seem daunting, and the costs out of reach. The fuses used by load interrupter switches to protect the transformer in an over current situation are no longer adequate. Current Load Interrupter Switches (LIS) may provide poor fault current interrupting times, resulting in high arc-flash incident energy.

ABB’s  Breakmaster V solution provides reduced Arc Flash incident energy levels for customers on their existing MV equipment. This new solution includes a fixed-mount IEC SecoVac* VB2 Plus vacuum circuit breaker (VCB) in the fused compartment of LIS. Operating in three cycles, the fast-acting SecoVac VCB offers a new Arc Flash mitigating solution designed in response to Arc Flash Safety Standards.

Features and benefits

The Breakmaster V solution reduces Arc Flash levels to help enhance safety and provides increased flexibility.

  • Reduced Arc Flash levels from the transformer down to the LV system
  •  Use as a main or feeder device which can also be part of a line-up that includes the fusible or unfusible Breakmaster LIS
  • Relay options that provide upstream and/or downstream communications
  • Maintains the same footprint as the fusible Breakmaster LIS
  • The added reliability and quality of an IEC-rated, fast-acting, 3-cycle Vacuum Circuit Breaker with embedded pole technology
  • Protection provided via the latest relay technology including bus and transformer differential options


  • American National Standards Institute (ANSI) Applicable sections of: 
  • ANSI/IEEE C37.20.3, C37.20.4, C37.22 - as existing and installed. 
  • IEC-62271-200 Standard
  • National Electrical Code (NEC)

Note: The Breakmaster V includes low voltage control wiring from the SecoVac circuit breaker and current transformers to terminal blocks located in the LV Compartment. Before energization, contact ABB Field Services or qualified personnel for wiring and programming of the factory-installed Multilin relay or any customer- specified or provided relays or components.