Hi Bostjan / Ted, Thanks for the information.
The pluggable type A equipment in question has a VDR + GDT in series in the PSU. Mains cord connection is Line, Neutral and Earth with earth terminating to the chassis inside the unit. There is also has a provision for a permanently connected earth conductor (external earth screw in chassis). The question is does the unit have to be permanently connected to earth? Or does just providing the provision for a permanent connection meet the requirement? Thanks, Chris. On 5 March 2015 at 14:13, Ted Eckert <ted.eck...@microsoft.com> wrote: > Hello Chris, > > > > Your equipment is required to have a provision for a permanently connected > earthing conductor. > > > > Section 1.5.9.4 gives you three options. > > · If your equipment has no permanent connections, it must be > Pluggable Type B. Since you have already described your product as > Pluggable Type A, this option isn’t available. > > · Your equipment can have a permanent mains connection. Again, > since you have Pluggable Type A, you can’t use this option. > > · This leaves the third option of providing a provision for a > permanently connected earthing conductor along with providing instructions > on its proper use. > > > > It is not prohibited from having equipment with a permanent earthing > connection yet pluggable line connections. This is an unusual and somewhat > impractical construction, but it is allowed. It’s not all that different > from the Japanese Class 01 plug. In Japan, grounded outlets are uncommon. > Most residential and commercial outlets are NEMA 1-15 with just line and > neutral. There is a strange plug in Japan that is allowed under Japanese > national differences to IEC 60950-1. The Class 01 plug > <http://www.quail.com/P-2013.098/Power-Cord--Quail-Pn-2013098--25m-125mm3-Vctf-Black-Nacc-Jis-8303-Japan-With-Ground-Lead-To-Roj.aspx> > has the line and neutral blades, but it also has a ground wire coming off > of it with a fork or ring lug. It isn’t exactly what would be required on > your equipment, but it does show that such constructions are used in Japan. > > > > Ted Eckert > > Compliance Engineer > > Microsoft Corporation > > ted.eck...@microsoft.com > > > > The opinions expressed are my own and do not necessarily reflect those of > my employer. > > > > *From:* Chris Allen [mailto:speedtrif...@gmail.com] > *Sent:* Thursday, March 5, 2015 5:16 AM > *To:* EMC-PSTC@LISTSERV.IEEE.ORG > *Subject:* [PSES] To earth or not to earth...... > > > > I'm looking for some views on IEC60950-1 Ed.2 + A2 section 1.5.9.4 > > > > If you have pluggable type A equipment that has a PSU with a VDR + GDT in > series bridging primary insulation does the equipment have to be > permanently connected to a protective earthing conductor? > > > > Section 1.5.9.4 states that equipment with such a VDR bridging basic > insulation shall be one of the following: > > - Pluggable Type B: or > - Permanently connected equipment: or > - Equipment that has provision for a permanently connected protective > earthing conductor and is provided with instructions for the installation > of that conductor. > > > > What this doesn't say is that it *shall* be permanently connected. > > > > Other sections in the standard where permanent connection is required say > just that e.g. section 2.3.2.3 "The installation instructions shall specify > that this separate protective earthing terminal be permanently connected to > earth". > > > > Any thoughts / views gratefully received. > > > > Thanks, > > Chris. > > > > > > - > ---------------------------------------------------------------- > > 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>
