A comparison of international residential grounding practices and associated magnetic fields

Measurements of residential power frequency magnetic fields have shown that a service entrance grounding system can be a source of magnetic fields in homes. Several typical service entrance grounding schemes found internationally are discussed. With growing interest in possible health effects from power frequency magnetic field exposure, the contribution to residential field levels from grounding system currents needs to be characterized. Should a future need arise to modify the field levels from grounding systems, a clear understanding of possible grounding scheme alternatives needs to be developed. The characteristic differences in residential grounding practices from several areas of the world are explored. No attempt is made to comprehensively describe all varieties of residential grounding schemes found worldwide, nor to discuss the relative merits of each scheme with respect to safety. Rather, observations of how grounding scheme differences in Australia, Germany, Japan, UK and USA can produce a variety of resulting magnetic field levels in homes are discussed