I read in !emc-pstc that Brian O'Connell <[email protected]> wrote (in <[email protected]>) about 'electric strength test' on Thu, 22 Aug 2002:
>A (new) agency engineer says that inserting a piece of insulator defeats the >purpose of the test. I don't see how. >For class 1 construction, it is just not possible for >me to pass 4300vdc test levels without inserting my little piece of valox, You need 4300 V only if the secondary circuits are SELV and thus isolated from the chassis. But this is very unusual. I suppose you could use two supplies, +2500 V from primary to chassis and -1800 V from secondary to chassis, but I've never heard of anyone doing that. An earthed screen between the primary and secondary windings in the transformer would overcome the problem another way. -- 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
