Foundation Earthing System – Its Application and Electrical Safety Considerations
Keywords:Foundation earthing system, Equipotential bonding, Residual Current Device, Earth loop impedance, Earth resistance
Foundation earthing system greatly reduces the resistance to ground as compared to driven earthing rods. Low resistance to ground is desirable to protect lives – it ensures disconnection of power supply by Residual Current Device in the event of leakage current to ground. However, special attention must be given in the application of foundation earthing system to terrace houses and shop lots, where common ground slab steelwork is used throughout the entire row of houses or shop lots. This paper shows the field tests and findings of terrace houses with foundation earthing system, the requirements of the design and installation of foundation earthing system, and the importance of such installation to achieve low resistance to ground, to be able to operate the protective devices for supply disconnection during fault condition.