Thanks for your kind comments about the
On Demand Arc Flash / IEEE 1584 ClassThe IEEE 1584 incident energy equations are based on a three phase arc flash so the direct effect of impedance grounding would not be seen. Here are a few points regarding impedance grounding and arc flash.
- Most faults originate as L-G so with impedance grounding it would limit the current and incident energy and not escalate into a three phase event. i.e. it would stop a large number of faults from becoming a three phase arc flash.
- Since IEEE 1584 is based on three phase arc flash, modeling single phase is not addressed and impedance grounding is not an issue in the calculations.
- The 2002 Edition of IEEE 1584 equations gave slightly different results for the three phase incident energy depending on whether the system was grounded or ungrounded/impedance grounded
- The 2018 IEEE 1584 equations did away with that difference. It had to do with the erratic nature of the arc during initiation which was filtered out be removing 2 cycles.
Hope that helps!