Arc Flash Calc

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Isaiah

Senior Member
Location
Baton Rouge
Occupation
Electrical Inspector
The 200A MCB protecting the switchback horizontal bus is a micrologic with LSIG - do any of these settings need to be adjusted due to the additional motor load - 15hp @ 21FLC?
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Per NFPA 70E, 130.5 (G): "The incident energy analysis shall be updated when changes occur in the electrical distribution system that could affect the results of the analysis. The incident energy analysis shall also be reviewed for accuracy at intervals not to exceed 5 years."

I really don’t see how these can be done as the rules state. What if the utility reconductors the line, changing the X and R, or changing the transformer, changing the Z. Now every calculation inside the premise is off. It isn’t the utilities responsibility to let every contractor know about system changes. That could be the reason for the five year revisit, but has anyone been asked to do a five year analysis, just because it’s been five years?
 

wbdvt

Senior Member
Location
Rutland, VT, USA
Occupation
Electrical Engineer, PE
I also have clients that do a 5 yr update and I have clients who send me changes within the 5 yr window in which I will usually do an addendum to the report to capture that change along with labels.
 

Hv&Lv

Senior Member
Location
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Occupation
Engineer/Technician
Just a question because we have VERY few call us about our transformers, and that’s only on connections or inspections..
do they have information regarding transformer changes on utility side?
 
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