rlorenz2 wrote:

I am preforming DC arc flash calculations for a system with a reactor having the following ratings: 250VDC, 1000A, 262.5KVA, and 4.05%Z. I have calculated the incident energy using NFPA 70E-2015 Section D.5 for the Maximum Power Method and looking to find the Arc Flash Boundary. Is it acceptable to use the Ralph Lee Calculation Method equation D.2.1(d) or (e) for determining the distance?, if so what "t" (time of arc exposure) would be used?

Thanks in advance.

Shouldn't be that hard since its basically a linear equation except for the D^2 term. Did you try solving it directly yourself?