Time-Current Coordination and Arc-Flash Study Summary: ZSI Reduces 14.2 to 3.8 cal/cm²

A time-current plot for a 100 A feeder and a 400 A main at 4500 A (0.084 s separation) with an arc-flash summary where zone-selective interlocking cuts the delay from 0.30 s to 0.08 s, lowering incident energy from 14.2 to about 3.8 cal/cm², plus notes on reading the plot.