There is no IEEE 1584 calculation for single phase circuits regardless of voltage so they are not normally part of arc flash studies therefore they rarely have a cal/cm² sticker on them.
If the calories or Hazard Risk Category (HRC) are not known you are only left with the 70E task tables. If the circuits are current limiting then you may be able to take advantage of the provisions that allow a reduction in the normal task table HRC.
How come the Wisconsin and UP guys are up at this time of night, don't you have to get up and shovel in the morning?
