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Short-Circuit & Per-Unit Studies

Bolted Three-Phase Fault: One-Line and Equivalent Impedance Diagram

A utility source, step-down transformer and 480 V cable to a bolted fault, drawn as a one-line and as a per-phase impedance circuit with the formulas I_f = E_s / (Z_s + Z_t + Z_c) and Z_eq = ΣR + jΣX, and a table defining each term.

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