Hi Jim:
> I don't understand why electromechanical devices cannot be > proven to have reliable cycle life. There are > electromechanical devices tested for 6,000 cycles and 100,000 > cycles commonly available, and there may be other classes > with even higher cycle life. For a circuit-breaker, why do we need 6,000 or 100,000 cycle reliability? Circuit-breakers probably are not operated even 100 cycles during their lifetime. A circuit-breaker need only be reliable for one cycle -- provided that it fails safely (open circuit). The marketplace will demand reliability, not the safety standards. Best regards, Rich - 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 emc-p...@ieee.org 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 emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc