If you use a branch or feeder from one building to supply power to another building, you generally can run only one branch or feeder for that purpose [225.30]. There are five conditions under which you can exceed this limit [225.30(A) - (E)]. The first one is "special conditions."
You can install additional feeders or branch circuits for:
Fire pumps (Art. 695)
Emergency systems (Art. 700)
Legally required standby systems (Art. 701)
Optional standby systems (Art. 702)
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