Any thoughts on whether infrastructure installed in a power generating station needs to comply with NFPA 70E or NESC requirements?

The introduction to NFPA 70E lists one of the items "not covered" as equipment under the exclusive control of an electric utility used for the purpose of generation and located on property owned or leased by the utility.

Alan

NFPA 70E does not apply to utilities. RUS funded organizations are required to meet the NESC rule. It may be different from state to state but I do know that WI has adopted the NESC rule.

My concern with using the NESC for in power plants is that a lot of equipment is 480V and per the NESC less than 1000 V is a minimum of 4 cal/cm2 clothing. I believe that a power plant is closer to a industrial plant and have used NFPA calcs for the AFH in the plant. I have seen many Cat #3 situations where, if going only by NESC, this would have been a 4 cal system.

I performed AF studies for "a large federally owned utilitity" and can tell you they are using the 1584 equations for their in-plant studies.
They also keep 70E as a reference, and often site it, but pick and choose which portions they should comply with. Certainly the NESC is used for all lines and out-of-plant issues.

wbd and WDeanN,

I agree with you. We recently completed an entire system AF Study for a local Utility and we used NESC for overhead distribution and IEEE 1584 equations for the Power Plant and Water Plant. I did not feel safe applying the NESC equations to the 480V switchgear in the Power Plant which was coming up as CAT 4 in many cases.