Hi Ron, This sounds like a problem I ran into before. I assume that the standard is 60950-1. If the unit has 2 power cords and can it operate with only one connected, you only have to measure the touch current with one power cord connected. Refer to 60950-1 clause 5.1.2 Equipment under test (EUT)
Regards Doug --- "Ronald R. Wellman" <rwell...@wellman.com> wrote: > Howdy all, > > I have come across a problem where a product is exceeding 3.5 > ma of touch > current. The product in question has 2 line filters and 4 > Switching Mode > Power Supplies. Because of the addition of the fourth power > supply the > overall touch current can be as much as 4.0 ma. Ideally, we do > not want to > make the product so it has to be hard-wired to the building > mains. > > Because of the high touch current, does anyone know what the > relationships > are between different touch current sources? I've heard that > touch current > is not linear when you add up the different sources and phase > shifts between > L-G and N-G might be a problem. However, I'm looking for some > detailed > information on this issue so I can provide ways to investigate > the problem > and hopefully reduce the overall touch current. > > BTW, the product is not medical equipment and all touch > current tests are > done with the product operating at 264 V AC, 50 Hz. > > Best regards, > Ron Wellman > > > 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/listserv/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Ron Pickard: emc-p...@hypercom.com > Scott Douglas emcp...@ptcnh.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: > > http://www.ieeecommunities.org/emc-pstc > ______________________________________________________________________ Post your free ad now! http://personals.yahoo.ca 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/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Scott Douglas emcp...@ptcnh.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: http://www.ieeecommunities.org/emc-pstc
