Requirements for updating short circuit and coordination studies

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mull982

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Does anyone know of a NEC reference or other reference that have requirements for when a short circuit and coordination study should be updated? In most cases I believe these studies should be updated anytime a significant change such as a facility expansion or the addition/replacement of electrical equipment.

Even without any changes taking place is there a documents requirement or suggestion for updating these studies? I know NFPA 70E 130.5 (2) requires AF studies to be updated every 5 years or when a significant change takes place, but I am looking for something that relates specifically to just the Short Circuit and coordination.

Should utility fault current contribution be reviewed/updated every so often to confirm that it has not increased due to changes no the utility system (even though most of the time utility just provides max let-thru on SE transformer)

Any requirements specifically related to healthcare facility?
 
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topgone

Senior Member
jim dungar said:
What is the OSHA rule require the updating of just device coordination and available short circuit current analysis?
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OSHA orders you the observe the General Duty clause (Section 5 of the OSHA Act). That covers everything needed to be done to ensure safety of your people.
But you can get your code book and go to Article 110.24(B) and see that you have to:
(B) Modifications. When modifications to the electrical installation occur that affect the maximum available fault current at the service, the maximum available fault current shall be verified or recalculated as necessary to ensure the service equipment ratings are sufficient for the maximum available fault current at the line terminals of the equipment. (snipped)
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jim dungar

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PE (Retired) - Power Systems
topgone said:
OSHA orders you the observe the General Duty clause (Section 5 of the OSHA Act). That covers everything needed to be done to ensure safety of your people.
But you can get your code book and go to Article 110.24(B) and see that you have to:
Click to expand...

So, if my original equipment is rated for 65,000 AIC and there is an installed label that reads 65kA available. Now, the utility says their system can deliver 51,000SCA (up from 34,000SCA), do I need to update my study?
NEC110.24(B) deals with the label at the service entrance. No where does the NEC require a complete facility study for just SC and Coordination.
 
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topgone

Senior Member
jim dungar said:
So, if my original equipment is rated for 65,000 AIC and there is an installed label that reads 65kA available. Now, the utility says their system can deliver 51,000SCA (up from 34,000SCA), do I need to update my study?
NEC110.24(B) deals with the label at the service entrance. No where does the NEC require a complete facility study for just SC and Coordination.
Click to expand...

Your equipment is rated above the available fault at the point of installation. No problem then!
 
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