MEASUREMENTS OF TOUCH AND STEP VOLTAGES ADOPTING MULTI CURRENT AUXILIARY ELECTRODES

With urban development and buildings growth adjacent to power systems, to choose suitable locations for auxiliary electrodes becomes increasingly difficult testing the resistance, the touch and step voltages Et and Es in a grounding system. Accuracy of tests requires reaching remote earth and for large grounds the spacing required may not be practical or even possible. Since the rigorous measure can result too much laborious or too much expensive, a simplified conservative testing method of the behavior of ground clectrodes can be favorable. The measure of touch and step voltages (Et , Es ) allows verifying the efficiency of grounding systems Opposite to the measure of ground resistance GR, the measure of Et and E, can be done with an auxiliary electrode at a reduced distance, since that it's possible to do that the error e% is positive and so the result is conservative. Furthermore adopting three or more current auxiliary electrodes, placed around the testing ground electrode symmetrically in homogeneous soil and with a measure special procedure in no-homogeneous soil, it is possible to achieve the important goals, of : - an error always conservative and with a more reduced value ; - lower potential values near the current