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# Transformer current

Turn a transformer kVA rating into primary and secondary full load amps, with ratios, loading table, fault estimate, and inrush band.

Enter a kVA rating and both winding voltages.

Read the fault figure for what it is: full-load current divided by the per-unit impedance with the supply assumed infinite, so it overestimates. A real study needs the source impedance and motor contribution per IEC 60909 before anyone sets a protection grade. Delta-star vector groups also shift the winding ratio by root-three relative to the line ratio quoted here.
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