I was curious what arc flash potential is there at 120 volts and if there is a cut-off as far as voltage to when an arc flash is no longer a possibility. I am having a hard time finding anything in writing.
Google is our friend. You need to do more research on how to calculate "incident energy." There is a lot of info out there. Here are a couple of articles:
Incident-Energy Calculations | Electrical Contractor Magazine
I also am confused about this condition. I believe Arc Flash is based on three phase calculations. All of the references listed above are based on a minimum three phase voltage of 0.208 kV not 120 Volts. Even though the authors of the references state that fault currents should be calculated for each point in the distribution systems, their examples are based on fault current conditions that generally may exceed the actual calculated fault current available.
Many times, the available fault levels are so low that molded case circuit breakers cannot trip fast enough to provide arc energy levels below Level 2 or Level 3. However, with the low available fault levels, is it even possible to sustain an arc?
What sustained energy levels are obtained if the available fault levels of 15 kVA, 50 kVA or even 75 kVA single phase transformers are less than 10 kA?
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