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May 29, 2020   photos  

Gravel/Stones in the Substation Switchyard is provided to reduce the step potential and touch potential when operators work on Switchyard. Step Potential: It is the potential developed between the two feet on the ground of a man when short circuit occurs. In addition to this, the main reasons are based on:
First of all, we use stone in our electrical substation for reducing the Ground Potential Rise (GPR) and in electrical engineering, it also called Earth Potential Rise (EPR) and it occurs when a large current flows to earth through earth grid impedance.
Stone increase resistance of soil, for this reason, step potential, and the touch potential limit decrease. When people are working in substations stone reduces the possibility of electric shock during work.