I read in !emc-pstc that Muriel Bittencourt de Liz <mur...@eel.ufsc.br> wrote (in <004c01c37861$f5de8e30$560aa...@maglab.ufsc.br>) about 'earthline choke' on Thu, 11 Sep 2003: >I also remember that I read somewhere (i think it was Clayton Paul's >book) that the use of this choke on safety wire is a problem for >conformity with the safety standards, so its use it is not recommended >from this viewpoint.
For safety, the requirements are a low enough impedance at the power supply frequency |(50 or 60 Hz, usually), and sufficient current- carrying capacity (typically 25 A for a few hundred milliseconds). The impedance requirement (applied to the whole primary supply) is usually more difficult to meet, being typically 0.1 ohm, including the mains cable, fuse and internal wiring, but assuming a zero-impedance short- circuit between (live + neutral) and earth. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
