GRAPH INDICATING CONDITIONS FOR INSTALLATION OF DEEPLY EMBEDDED INDEPENDENT INSULATED GROUND ELECTRODE

摘要

PROBLEM TO BE SOLVED: To provide an installation method using a deeply embedded independent insulated ground electrode for electrical insulation from the other grounding systems, considering mutual grounding interval of a plurality of ground electrodes and mutual interval for the grounding interval to the underground portion of buildings or the like.;SOLUTION: The graph indicating conditions for installation of deeply embedded independent insulated ground electrode includes the horizontal axis which is graduated with the logarithmic scale, in the range from 0.5 to 100 of the value N representing a ratio t/r between the equivalent semispherical body radius 4 corresponding to the insulation depth of the insulated independent ground electrode and the embedding depth t thereof; the vertical axis which is graduated with the logarithmic scale in the range from 1% to 100% of a voltage spreading coefficient αfrom the ground electrode, and with the variation coefficient η in the range from 1.01 to 2 of the equivalent radius (r) of semi-spherical body changing depending on the depth; the first linear line connecting the position where N is 1 and α is 100%, and the position where N is 100 and α is 1%; and the second linear line connecting the position where N is 0.5 and η is 2 and the position where N is 50 and η is 1.0. Therefore, the voltage spearing coefficients α and η are obtained from the value on the vertical axis of the linear line corresponding to the desired n.N value (here, n is 0.5 to 100) on the horizontal axis.;COPYRIGHT: (C)2002,JPO