Three Phase Arc Flash Boundary in ARCPRO

[DistCoop]

How do you guys handle determining three phase arc flash boundaries using ARCPRO? Single phase arc flash boundary can be achieved with trial and error, continually adjusting the working distance until your incident energy at that distance is equal to 1.2 cal/cm2. But what about three phase?

Could you say that the chances of a three phase arc are too remote due to the greater spacing at 69kV and 115kV? If so, then what about the low spacing of 25kV or 35kV?

We're not sure how to proceed on this front and would welcome any experience. Thanks

 

[wbd]

Remember that ArcPro is for single phase open air faults. They do provide a multiplier for 3 phase arcs. Typically on utility overhead systems the spacing is such that a 3 phase fault is unlikely but that would have to be determined by a risk analysis.

One way to determine the boundary for a 3 phase fault is to use the multiplier to determine the 3 phase incident energy and then look on the table of results from the case study for the distance at that value.

Also note that OSHA requires AR PPE at 2 cal/cm2 not 1.2 cal/cm2.