It has been a while since a question of the week was asked about the Arc Flash Boundary. This is the distance from a prospective arc flash where the incident energy is 1.2 cal/cm^2 which is the generally accepted value for the onset of a second degree burn. IEEE 1584 has a method for calculating this distance.

Since electrical safety practices continue to evolve, this week's question is about the Arc Flash Boundary. Although the AFB is required to be on the warning label and is a calculated value, many are opting to keep unprotected/unqualified workers further away from a possible arc flash during live work (which should be kept to a minimum). This week's question:

For your (client's) electrical safety practices, do you use:
Select up to 2 answers

Calculated AFB
Something larger (please explain)
Keep unprotected people out of the electrical room
It depends

Please feel free to elaborate

I've had some buses where the "calculated" value is outright ridiculous...like hundreds of feet. Even if this was realistic, the building walls would come into play so at that point the building/room size matters, not the calculated number.

Good point! I forgot about that case.