I read in !emc-pstc that Peter L. Tarver <peter.tar...@sanmina-sci.com> wrote (in <nebbkemlgllmjofmoplekemhegaa.peter.tar...@sanmina-sci.com>) about 'Safety testing after equipment repair' on Thu, 22 May 2003:
>Or a lower potential test for mains connected equipment, >such as insulation resistance. No, an IR test is not a substitute for a hi-pot test, and has a can of worms all its own. Pass values of leakage resistance are in the megohm range, but much modern equipment starts off in the 100 megohm or even gigohm range. So a degradation to 1 or 2 megohms could well be a sign of seriously-damaged insulation, but the equipment is regarded as OK. In my opinion, a value less than one-third of the initial value (preferably specified by the manufacturer) is a cause for concern. > >More complicated, but less deleterious, tests could include >an earth leakage current test or a touch current test. > Earth leakage is often appropriate but it is necessary to distinguish between resistive leakage and capacitive current. I don't know of any snags with touch current testing IF the IEC 60999 meter is used. -- 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
