Per NFPA 70E - 130.3, The arc flash hazard analysis shall be updated when a major modification or renovation takes place.

Does anyone know what constitutes a "renovation"? I understand that if you add a panel, MCC or switchgear that the arc flash analysis should be revisited. Where would one draw the line on when a study needs to be redone and does anyone have something in writing that clearly defines where this line is drawn?

Thank you

It all depends.

Are the results of the study affected?

Adding a 50HP motor to an existing MCC could be considered major.
But, replacing service entrance equipment while reusing all of the existing conductors and protective device settings could be considered as non-major.

If you are adding or deleting major pieces to the Distribution System, I think a good design pratice would be to revisit the effected areas and modify the study as needed.. JMO...

I believe that anything that will change the fault current (i.e. additions of large motors. New larger utility transformer installed, etc.) or any changes in the protective devices (manufacture or type) or their settings will impact the AF energy and boundary calculations. Furthermore, any new equipment must have AF labels with the HRC and AF Boundary listed.

In some cities in the State of Washington, it is manditory to include AF lables (with the details) for any new equipment installed. Please see the article -

http://www.powerstudies.com/AreyourSpecsReadyforWACitiesElectricalCode.htm

I would agree with both glen1971, and Robertefuhr. Anytime that you modify a system to taht extent you need to re-evaluate how these changes effect the total system.