NEC 700.3(F) - Temporary Source of Power for Maintenance or Repair of the Alternate Source of Power.

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anbm

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NEC 700.3(F) - Temporary Source of Power for Maintenance or Repair of
the Alternate Source of Power.

Regarding above rule, my understanding this rule only apply to emergency system / generator (article 700),
not

1) Legally standby system (article 701) or
2) Critical and equipment branch of Essential power system (article 517.31A)
except Life-safety branch (NEC 517.26)... i.e. The temporary generator can be sized large enough to
serve Life-Safey Load only in this case?
 
I think you can read 517.30 as requiring that for all essential electrical systems. If the alternate source is down for maintenance, then you no longer have the two required sources available.
 
There is no similar new rule in 701, so I would say the requirement does not apply to legally required standby systems. As to article 517, I find it difficult to sort through its rules in the context of the article 700 term "emergency."
 
"517.26 Application of Other Articles. The life safety branch of
the essential electrical system shall meet the requirements of
Article 700"

I assume this meant only Life-Safety load or Life-Safety ATS is required to comply with NEC 700.3(F)? as minimum. This makes a huge cost difference in lieu of backing up all three branches of ATSs load listed in 517 with portable generator?
 
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