# Performance Optimization of Grounding System for Multi-Voltage Electrical Installation
## 4 Grounding Configurations and Optimization Techniques  
### Conventional Grounding Electrodes  
Conventional earthing entails burying a copper plate or galvanized iron (GI) pipe within a pit layered alternately with salt and charcoal. This method requires regular water replenishment and periodic maintenance to ensure effective grounding. Conventional grounding electrodes include single rod electrodes and multiple rods, commonly used in  
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Parameter** & **Unit** & **Calculation Method** & **Standard/Limit** \\ \hline Ground Resistance & Ohms & Calculated from Wenner or Schlumberger method & Minimum value as per NEC \\ \hline Step Voltage & Volts & Measured during fault condition & \(\leq\)430 V (IEEE 80-2013) \\ \hline Touch Voltage & Volts & Measured during fault condition & \(\leq\)430 V (IEEE 80-2013) \\ \hline Fault Current Dissipation Efficiency & Percentage (\%) & \(\eta_{fault}=\frac{I_{dissipated}}{I_{total}}\times 100\) & Maximized for safety and reliability \\ \hline \hline \end{tabular}
\end{table}
Table 3: Evaluation criteria for grounding system optimization.  
electrical grounding systems [16]. The resistance of a single vertical rod electrode can be estimated using the following equation:  
\[R=\frac{\rho}{2\pi L}ln\left(\frac{4L}{d}\right) \tag{12}\]  
where \(R\) ground resistance (\(\Omega\)), \(\rho\) = soil resistivity (\(\Omega\cdot\)m), \(L\) = length of the rod (m), \(d\) = diameter of the rod (m). As the length of the rod \(L\) increases, the resistance \(R\) decreases, leading to a more effective grounding electrode. A larger diameter \(d\) reduces the resistance, as a wider surface area allows more current to flow into the ground. The soil resistivity \(\rho\) has a direct impact on the resistance, with dry or rocky soil having higher resistivity, and moist, sandy, or clay-rich soil exhibiting lower resistivity.  
In many practical applications, a single rod may not provide sufficient grounding, especially in areas with high soil resistivity [17]. To overcome this, multiple rods are used in parallel to reduce the overall grounding resistance. The resistance of the system with multiple rods depends on the number of rods nnn, their spacing, and the configuration in which they are arranged. For multiple rod configurations, the overall resistance \(R_{n}\) is reduced as given by the following:  
\[R_{n}=\frac{R}{n}K_{n} \tag{13}\]  
where \(n\) denotes the number of rods and \(K_{n}\) is a spacing factor dependent on the configuration. The spacing factor \(K_{n}\) can be estimated from empirical data or specialized charts that correlate the spacing of the rods and the configuration type with the resulting resistance. The closer the rods are spaced, the more effective the grounding system will be, as the total surface area for current dissipation increases. However, if rods are placed too close to one another, their individual effectiveness may be reduced due to mutual coupling effects, which can increase the total system resistance.  
For example, if the rods are placed in a linear arrangement, the resistance will decrease more slowly as the number of rods increases. However, if the rods are arranged in a triangular or rectangular grid pattern, the resistance will decrease more efficiently, especially at larger spacings. Figure 2 displays the conventional grounding system arrangements [18].