Arc Flash - Levels A B C D

[Geneapi]

My company had an Arc Flash study done by an outside electrical contractor and when they finished and provided a one line power diagram wit the ratings for all our equipment, I noticed that there were some labels above the ratings that were as follows

Level D
AFB + 4.23 ft
IE = 9.54 Cal/CM2
FCT = 1.828 sec

I have never seen this before and wonder if it is related category ratings any help would be appreciated.

Thanks in advance
Gene

 

[steve66]

bump - moved from the lighting forum.

 

[wbdvt]

My company had an Arc Flash study done by an outside electrical contractor and when they finished and provided a one line power diagram wit the ratings for all our equipment, I noticed that there were some labels above the ratings that were as follows

Level D
AFB + 4.23 ft
IE = 9.54 Cal/CM2
FCT = 1.828 sec

I have never seen this before and wonder if it is related category ratings any help would be appreciated.

Thanks in advance
Gene

Not entirely clear what your question is. It seems like the company has set up their own internal arc flash levels. Typically these would have a range of incident energy associated with them and that would be published. For example:
Level A 0-1.2 cal/cm2
Level B >1.2 - 12 cal/cm2
Level C >12-40 cal/cm2
Level D >40 cal/cm2

However without the company levels, all one can say about the label is that the Arc Flash Boundary is 4.23 ft, Incident Energy is 9.54 cal/cm2 and the Fault Current Trip is 1.828 sec.

 

[Sunny_92]

My guess would be that the company used their own system of hazard levels (A, B, C, D...) in order to create a clear distinction from the NFPA PPE Categories.

Also, in ETAP, the default incident energy levels for NFPA 70E 2012 to 2015 use letters (A, B, C, D...) instead of numbers.

If the company did their job well they should have provided you with a written report that explains the levels and their associated incident energy ranges.