Maximum Permissible Values of Step and Touch Voltages with Special Consideration to Electrified Railroads

Numerous experiments on animals and on the human body have shown that in order to size a grounding system for an electric installation, it is more correct to apply the allowable values of step and touch currents rather than those of step and touch voltages. Following a brief discussion of electric current through the human body and the various parameters of interact, values obtained are compared with values given in the IEEE Guide, IEC Standard, and in some other texts. Data available are insufficient to determine the correlation between body weight and maximal nonfibrillation current. Based on these and other findings by different authors, conclusions have been drawn and applied to electrified railroads.