Method of measuring earth ground resistance of a pylon

Abstract

The present invention relates generally to a facilitated method for accurately measuring the earth ground resistance of a ground rod, in particular a footing of a pylon acting as a ground rod or a ground rod attached to the footings of a pylon, and obtaining an overall value for the resistance of the pylon i.e. all footings in parallel, and all pylons connected in parallel thereto. A method of determining the earth ground resistance of two or more pylon footings is provided according to the present invention, comprising conducting selective measurements of each footing of a pylon consecutively and wherein true values for the resistance of each footing measured are calculated. According to the present invention the testing means is connected directly to two auxiliary electrodes which are placed at predetermined distances from the pylon, and a current measurement means which is placed around a pylon footing in order to measure a the current flowing along the footing.

1 . A method of determining the earth ground resistance of at least one selected pylon footing comprising the steps of:
 connecting a testing device to a pylon footing, to first and second auxiliary electrodes, and to a current measurement device;   placing said first and second auxiliary electrodes in soil at predetermined distances from the pylon footing;   wherein, for each selected pylon footing:
 the current measurement device is placed around the footing; 
 an alternating current of at least one predetermined frequency and voltage is applied between the pylon footing and the first auxiliary electrode; 
 the voltage drop between the pylon footing and the second auxiliary electrode is measured; 
 the current through the pylon footing using the current measurement device is measured; and 
 an earth resistance value is calculated for the pylon footing, based on said predetermined voltage and frequency values and measured current values. 
   
     
     
         2 . The method of  claim 1  comprising calculating the overall grounding resistance of a pylon based on the resistances of all parallel connected pylon footings. 
     
     
         3 . The method of  claim 1  wherein determining the earth ground resistance comprises for each selected pylon footing:
 determining the complex components of the voltage and current; and 
 calculating a complex grounding impedance value of the footing. 
 
     
     
         4 . The method of  claim 3  wherein the complex grounding impedance is characterized using at least one of polar form with magnitude and phase and Cartesian form with real and imaginary parts. 
     
     
         5 . The method of  claim 3  comprising calculating the overall complex grounding impedance of a pylon based on the complex grounding impedances of all parallel connected pylon footings. 
     
     
         6 . The method of  claim 1  comprising repeating the aforementioned steps for a plurality of pylons. 
     
     
         7 . The method of  claim 1  wherein said current measurement device comprises a clamp. 
     
     
         8 . The method of  claim 7  wherein said clamp comprises at least one of a standard clamp, a flex clamp, a current transformer clamp, a Flux gate clamp, and a Hall effect clamp. 
     
     
         9 . The method of  claim 1  wherein said testing device comprises data storage means operative to store measurement data. 
     
     
         10 . The method of  claim 1  wherein said testing device includes a main unit and a remote unit adapted to communicate with one another. 
     
     
         11 . A method of determining the earth ground resistance of at least one selected pylon footing comprising the steps of:
 connecting a testing device to a voltage generation means and to an alternating current measurement device;   wherein, for each selected pylon footing:
 the voltage generation means and current measurement device are placed around the footing; 
 a voltage is generated in the pylon footing using the voltage generation means; 
 the current induced by said voltage along the pylon footing using the current measurement device is measured; and 
 an earth resistance value is calculated for the footing, based on said voltage and measured current values. 
   
     
     
         12 . The method of  claim 11  comprising calculating the overall grounding resistance of a pylon based on the resistances of all parallel connected pylon footings. 
     
     
         13 . The method of  claim 11  wherein determining the earth ground resistance comprises for each selected pylon footing:
 determining the complex components of the voltage and current; and 
 calculating a complex grounding impedance value of the footing. 
 
     
     
         14 . The method of  claim 13  wherein the complex grounding impedance is characterized using at least one of polar form with magnitude and phase and Cartesian form with real and imaginary parts. 
     
     
         15 . The method of  claim 13  comprising calculating the overall complex grounding impedance of a pylon based on the complex grounding impedances of all parallel connected pylon footings. 
     
     
         16 . The method of  claim 11  comprising repeating the aforementioned steps for a plurality of pylons. 
     
     
         17 . The method of  claim 11  wherein said current measurement device comprises a clamp. 
     
     
         18 . The method of  claim 17  wherein said clamp comprises at least one of a standard clamp, a flex clamp, a current transformer clamp, a Flux gate clamp, and a Hall effect clamp. 
     
     
         19 . The method of  claim 11  wherein said testing device comprises data storage means operative to store measurement data. 
     
     
         20 . The method of  claim 11  wherein said testing device includes a main unit and a remote unit adapted to communicate with one another.