I read in !emc-pstc that raymond...@omnisourceasia.com.hk wrote (in <of5099731c.c8b3ec7a-on48256ab0.004e0...@omnisourceasia.com.hk>) about 'Manufacturing Hipot Testing', on Wed, 22 Aug 2001:
>I have read one BSEN standard suggesting not to perform hipot testing at >the test voltage, 3kV, 1.25kV or 3.75kV in mass production. Which one? That is vital! > The reason is >that it might introduce potential failure in future operation by the >customer not immediate failure. It also suggests if hipot testing is done >on production line, lower testing voltage, i.e., 1/2 of test voltage should >be applied. I would like to have comments on this concern while doing >hipot test on production line or other modern way to replace the hipot test >on production line. I think this is being over-cautious, maybe dangerously so. There is a good reason for using such high voltages, based on typical surge or spike voltages plus a margin - failures may not be detected at lower voltages. The concern over gradual degradation of insulation was brought up in the context of 'PAT' - Portable Appliance Testing, where products **in service** might be tested every three months or even at shorter intervals. In this case, it is now the practice not to do a hi-pot test at all, but an insulation resistance test. (There is a problem with this as well, but that's another subject.) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Eat mink and be dreary! ------------------------------------------- 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: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
