Sting wrote: OMG that's 4 or more now and as Yanchee points out-- just the tip of the iceberg ---> such as: ground wires ( trace wire) on the NG gas lines that enter vie two meters attached to the various buildings - sub panels and ground rods in at least three other locations
Earth ground must provide equipotential and conductivity. In your case, conductivity exists. By implementing preferred or right solutions from this utility, then equipotential (single point earth ground) is created. Interconnecting wires are outside and buried. Buried wire gauge and minimum depth is defined by local electric codes for human safety. A tech tip demonstrates good, bad, and ugly (preferred, wrong, and right) solutions: http://www.duke-energy.com/indiana-busi ... tip-08.asp
Unplugging is a least reliable solution since most surges occur before anyone even thinks about unplugging. And since so many household devices cannot be unplugged. A useful solution means everythng is protected without depending on something that is unreliable. By manually disconnecting everything (including all clocks and smoke detectors) in a building.