HI John:
As mentioned in my first response, you will have the same problem (half the mains on the enclosure) if you use a Class II power supply. If you talk with your NRTL, I'm sure he will accept your construction based on 60950-1, 5.1 rather than 60950-22. Your equipment is not unsafe with the ground open if it complies with 5.1. (And it will!) Best regards, Rich ----- Original Message ----- From: John Cochran <[email protected]> Date: Monday, September 8, 2014 8:04 am Subject: Re: [PSES] UL 60950-1 clause 2.2.3 > It appears that I can only meet this requirement for outdoor > enclosures by either using a Class 2 power supply, or require the > installer to use the external ground connection in addition to the > internal PE ground. The system is safe under normal conditions, > but only has hazardous voltages on the enclosure when the PE ground > is broken. Are there any opposing opinions? > > John Cochran > STRONGARM Designs > 425 Caredean Drive > Horsham, PA 19044 > PHONE: 215-443-3400 X193 > FAX: 215-443-3002 > > -----Original Message----- > From: John Woodgate [mailto:[email protected]] > Sent: Monday, September 08, 2014 2:42 AM > To: [email protected] > Subject: Re: [PSES] UL 60950-1 clause 2.2.3 > > In message <[email protected]>, dated Sun, 7 > Sep 2014, Rich Nute <[email protected]> writes: > > >I believe the authors of 60950-22 expected that user-accessible > parts > >would comprise SELV circuits rather than grounded parts. See > 2.1.1 and > >2.2 in 60950-1. > > > >Grounded parts would be subject to 5.1 in 60950-1. > > Thank you. So what can the OP do? Does this need to be taken into > account in a revision or replacement of 60950-22? > -- > OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk > Quid faciamus nisi sit? > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK > > - > ---------------------------------------------------------------- > 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 <[email protected]> > > 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 <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> > > - > ---------------------------------------------------------------- > 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 <[email protected]> > > 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 <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> > - ---------------------------------------------------------------- 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
