Q323 : Computing Touch Voltages with FFTSES.

Question
How can I compute transient step and touch voltages with HIFREQ and FFTSES?

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Answer
HIFREQ/FFTSES can be used to compute transient earth potentials, touch voltage or step voltages, although only one at a time. To do this, go to the Database Management screen in FFTSES (Input Toolbox | Computations | Computation Type -> Inverse-FFT | Specify Input Type -> Extract From Database | Database Management). You can use the right-hand side of that screen to specify which quantities to extract from the HIFREQ computation databases. Select Scalar Potentials. The drop-down underneath this check-box offers three options (Potential, Touch Voltage to Nearest Conductor, Step Voltages) that corresponds to the earth potentials, touch voltages and step voltages.

In order for these options to work, the Scalar Potential should have been computed at the desired locations in the HIFREQ runs. You can also extract the Electric and Magnetic fields, as well as the conductor related data if those were computed in HIFREQ; these last options are independent of the Scalar Potential option.

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