Use of Instantaneous Trip Functions and Current Limiting Fuses to Reduce Arc Flash Energy

Abstract

The instantaneous trip can be used to reduce arc flash energy levels at 600 volt and 5 kV MCCs by minimizing the time to clear faults. The instantaneous is often not used since coordination with large motor starters can be lost. Which is more important? A digital multifunction relay may be able to use the Fourier transform algorithms for the instantaneous trip function to improve coordination with current limiting fuses in starters