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Short Circuit Current

Estimate 3-phase symmetrical short-circuit current at a bus from upstream transformer data.
Method: Isc ≈ (kVA × 1000) / (√3·V) × (100 / %Z). Ignores upstream source impedance/X/R.
Standards: IEEE 551/141 methods; NEC 110.9/.10 for interrupting/withstand checks.