Hi Richard, Apart from the insulation damage, we have to consider the electronic circuitry damage during hi-pot test. With good design taking care the impact of hi-pot test, the damage can be negligible but some electronic designers may not be familiar with hi-pot test impact and result in potential damage or degrading of the circuitry.
Some end product manufacturers do not do any safety test in production and take the excuse that the power supply manufacturer has done it in their production. For example, pc manufactures. If the transportation and handling are perfect, their excuse may be right. In reality, those stages are difficult to guarantee the perfection. Regards, Scott On 23/06/2011 5:58 AM, "richardn...@comcast.net" <richardn...@comcast.net> wrote: > Hi Richard: > > > Insulation breakdown starts with partial discharge in > very small voids. PD takes time to form. It usually > won't get started in the typical 1-minute hi-pot test. > After the voltage is removed, any ionized air in the > void slowly dissipates, so the PD event starts from > zero at the next test. > > At last year's PSES Symposium in Boston, there were > two presentations on insulation breakdown mechanisms. > > Some years ago, I connected several power supplies in > parallel to a hi-pot tester. I ran the tester for 8 > hours/day, 5 days/week. After about 1-1/2 weeks, I > detected some insulation abnormalities. > > At the relatively low voltages that we use for hi-pot > testing, the very good typical insulations, and the > low frequency of recurrence of the test, damage to > insulation is not likely. > > Don't worry about it. > > > Best regards, > Richard Nute > Product Safety Consultant > Vancouver, Washington > > > > - > ---------------------------------------------------------------- > 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://product-compliance.oc.ieee.org/ > Graphics (in well-used formats), large files, etc. can be posted to that URL. > > Website: http://www.ieee-pses.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...@radiusnorth.net> > 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://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.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...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
