Network analysis of ground currents in a residential distribution system

Ground currents on distribution system wires and metal water pipes have been measured at a residential magnetic-field research facility in order to increase understanding of sources of magnetic fields in the home. An analytical method with good simulation capability based on an electrical network model and providing formulas for calculating resistances and self-inductances for all wires and pipes and mutual inductances for pairs of conductors. At the site considered, resistances of joints between pipes in the water main were found to be significant. When joint resistances were included in the model, the difference between measured and calculated ground currents decreased from 89% to 20%. The need to include mutual inductance is discussed