With no more info than you have provided, some worst case numbers may be calculated assuming for magnetic field that the return conductor is infinitely far away, and for electric field that the return conductor is ground. With these assumptions, the magnetic field is:
H = I/(2 pi r) or B = uI/(2 pi r) Where I = power line current in Amps, R is distance from power line in meters, and u = permeability of free space = 4 pi x 1e-7 H/m The electric field on the line that is a perpendicular drop from the overhead power line is: E = V/h, where, V is the power line potential and h is height of line above ground. Both these equations will give worst case estimates. Ken Javor Phone: (256) 650-5261 > From: "Kunde, Brian" <[email protected]> > Date: Wed, 9 Jan 2008 09:39:40 -0500 > To: <[email protected]> > Conversation: Calculating Fields Strength from Power Lines > Subject: Calculating Fields Strength from Power Lines > > Greetings, > > We have a customer who wants to install one of our instruments in a room > with a high voltage power line running overhead. They say it is 110KV @ > 100Amps 50hz. I don't know the distance but I assume it is less than 10 > meters. I know there are a lot of factors, but with the limited > information I do have, it there a formula I can use to calculate what > the magnetic and electromagnetic fields could be present at any given > distance? Some ballpark numbers would be good enough, I think. > > Thanks, > The Other Brian > > LECO Corporation Notice: This communication may contain confidential > information intended for the named recipient(s) only. If you received this by > mistake, please destroy it and notify us of the error. Thank you. > > - > ---------------------------------------------------------------- > 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 - 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
