A field study on the energy dissipation associated with step and touch voltage in earthing systems encased in earth enhancing compounds

An extensive field experiment was conducted to investigate the effects of earth-enhancing compounds on earthing systems. Four identical vertical earth rods were installed, each encased in concrete, Bentonite, and two commercial enhancing materials. Lightning impulse signals were injected into all electrode arrangements, and the measured responses were used to analyse the associated risks of step and touch voltages. The peak voltage values and the corresponding energy dissipation for each measurement were calculated and compared to those of a reference electrode. The analysis of step voltage measurements and the corresponding energy dissipation demonstrated that the use of concrete exhibited greater advantages than the use of Bentonite. However, touch voltage measurements and the associated energy dissipation indicated that despite the lower touch voltage exhibited by Bentonite, its energy dissipation exceeded that of the reference electrode. Consequently, the unique findings reveal that specific variations of earth-enhancing compounds can exhibit reduced earth impedance and lower step or touch voltages while also yielding higher energy dissipation, introducing an unforeseen risk of injury. © 2017 Elsevier Inc. All rights reserved.