Hi Brian:
If the neutral is grounded at two points or more, then the earth is in parallel with the neutral and will carry some portion of the neutral current that flows between those two points. This current will cause a potential difference (voltage) between two points of the earth near or on the current pathway. The NEC requires the neutral to be grounded at the service entrance to a building. If the supply to two buildings is from the same source, then some portion of the neutral current will flow through the earth between the two buildings. Of course, a copper neutral wire likely has much lower resistance than the earth. Nevertheless, current will flow through the earth, especially if the earth is highly conductive between the two ground points. Best regards, Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
