4 ms·
Arcs are rated by calories per square centimeter. There's a lot factors that go into arc ratings, more than just voltage. To give a frame of reference, a flam
by c_o_n_v_e_x 4y ago
Arcs are rated by calories per square centimeter. There's a lot factors that go into arc ratings, more than just voltage. To give a frame of reference, a flame from a lighter on the tip of your finger for 1 second is considered 1 calorie. Arc flash PPE ratings start at 4 calories and can go above 100.
The high cal rated PPE does indeed look like bomb squad gear.
- MayeulC 4y agoIt's weird to rate it in calories (∝ joules, W.s) instead of Watts.
- closewith 4y agoEnergy is used rather than power as it's the cumulative effect in energy incidents that causes damage. In most of the world, the unit is J/cm2, though.
- MayeulC 4y agoAh, all right, I understand if it's used to rate accumulated damage for incidents. For ongoing arcs, or comparing them however, I think it's a weird. A small arc, not even dangerous to touch, could have the same energy rating as a gigantic one if you measure the first over a year and the second over a millisecond.