Charlie, The spacing between the pads where the SMT resistor is mounted may be so small that the resistor failure mode doesn't matter. The creepage distance itself may require consideration of a short between the pads as a valid single fault condition..
Gregory H. McClure Lexmark Product Safety 859 232 3240 office 859 232 6882 fax On Mon, Nov 17, 2014 at 4:40 AM, Charlie Blackham < char...@sulisconsultants.com> wrote: > All > > > > Have a discussion with an NRTL regarding fault testing on the > charge/discharge circuit for a 65mAh 3.1V coin cell battery in product > being assessed against 60950-1. > > > > The NRTL insist on short-circuiting the single 560R current limiting > resistor and I am unable to find any evidence that thick-film or thin-film > surface mount resistors can fail short-circuit as they appear to fail > open-circuit > > > > Now, we could add a 2nd series resistor, but that would require a board > change - can SMT resistors fail this way, or are the NRTL being > over-enthusiastic (unreasonable) > > > > Thanks > > Charlie > > > > *Charlie Blackham* > > *Sulis Consultants Ltd* > > *Tel: +44 (0)7946 624317 <%2B44%20%280%297946%20624317>* > > *LinkedIn: **uk.linkedin.com/in/charlieblackham/* > <http://uk.linkedin.com/in/charlieblackham/> > > *Web: www.sulisconsultants.com <http://www.sulisconsultants.com/>* > > Registered in England and Wales, number 05466247 > > > - > ---------------------------------------------------------------- > > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to < > emc-p...@ieee.org> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in > well-used formats), large files, etc. > > Website: http://www.ieee-pses.org/ > Instructions: http://www.ieee-pses.org/list.html (including how to > unsubscribe) <http://www.ieee-pses.org/list.html> > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org> > David Heald <dhe...@gmail.com> > - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
