There seems to be a discrepancy from different people I have had discussions with regarding the cal/cm2 min/max rating for the appropriate PPE Level. My understanding is that PPE level 1 is 0 - 4 Cal/cm2 incident energy exposure, PPE Level 2 is 4.1 - 8 Cal/cm2, PPE Level 3 is 8.1 - 25 Cal/cm2 and PPE Level 4 is 25.1 - 40 cal/cm2. The minimum rating of the AR Clothing for that PPE Level, 4 cal/cm2, 8 cal/cm2, 25 cal/cm2 and 40 cal/cm2, which I understand is that the maximum incident energy for that PPE Level. Therefore the maximum incident energy can't exceed the minimum level of PPE required for that level, Am I correct on this?

It seems some people are in the assumption that the minimum incident energy for that PPE Level is what is shown. I had this discussion with an NFPA 70E Arc Flash Instructor yesterday and she had me confused. She stated that PPE 1 is 4 - 7.9, PPE 2 is 8 - 24.9, PPE 3 is 25 - 39.9 and PPE 4 is exactly 40.

Rene, I understand where there may be some confusion but as I read the text of Table 130.7(C)(16) I would agree with the instructor of your arc flash training course. The article read literally states "PPE Category 1: Arc-Rated Clothing,...(I will stop here and place an emphasis on the coma as being a delineation or separation point) Minimum Arc Rating of 4 cal/cm2"

If we break this down as such;

PPE Category 1

Arc Rated Clothing (Required)

(Minimum) Arc Rating of 4 cal/cm2

PPE Category 2

Arc Rated Clothing (Required)

(Minimum) Arc Rating of 8 cal/cm2

I appreciate your questions and comments, honing our skills and knowledge is a community effort!