A study of earthing system using reinforcing bars in house foundation using by real scale experimental model

An earthing system that uses a house foundation was designed. The earthing resistance of the minimum experimental mat foundation model (about 1.3m² in area) on outdoor was less than 90 Ω at over 100 kHz on a lightning surge equivalent frequency and stayed between 30 Ω and 50 Ω over time. When the earthing system was constructed in the house, it was suggested that it could be applied as a less-than 100 Ω earth because the impedance resulted capacitive from the frequency characteristics. The earthing system with surge protection devices suggested having the overvoltage control effect.