Transformer
Calculate transformer full load current and impedance.
Questions
Each answer describes what this tool calculates. The result is a design aid. Verify against the current standard.
What does the transformer calculator do?
The tool reports the primary full load current, the secondary full load current and the secondary fault current. It works from the rating in kilovolt amperes, the primary and secondary voltages, the impedance percent and the phase count.
Which inputs matter most?
The rating and the two voltages set the two full load currents. The impedance percent sets the secondary fault current: a lower impedance gives a higher fault current. The phase count applies the square root of three to both currents.
What are the common gotchas?
The fault current assumes an infinite upstream source, so it is a worst case figure and the tool says so with every result. Cable and network impedance are not included. The impedance percent is limited to 30. The inputs sit in the page address, so a link reproduces the result.