Adam –
Brian’s suggestion I a good one. Answer from electrician should include three 20 A, two-pole branch circuit breakers for each single-phase load, possibly one main 45 A, three-pole breaker (with dependencies), plus Neutral bar (if needed) and ground bar. Miscellaneous assorted potpourri to fit the application. Regards, Peter Tarver *From:* Adam Dixon [mailto:lanterna.viri...@gmail.com] *Sent:* Thursday, August 20, 2015 13:36 *To:* EMC-PSTC@LISTSERV.IEEE.ORG *Subject:* Re: [PSES] 208V/30A/3PH NEMA 3R power distribution question Thanks for the suggestion, Brian. I just contacted the company that did some of my office building's infrastructure, so will see how that goes. Regards, Adam On Thu, Aug 20, 2015 at 4:16 PM, Brian Oconnell <oconne...@tamuracorp.com> wrote: Have you talked to a certified industrial electrician? Had a customer that bought several 250kVA distribution transformers that also wanted some custom wiring harness and downstream panel boxes. So hired an industrial electrician to advise us on materials and build it up. Passed on-site assessment with no problems. Probably saved hundreds of hours of engineering time, and $$$$$ in wasted material costs. Brian From: Adam Dixon [mailto:lanterna.viri...@gmail.com] Sent: Thursday, August 20, 2015 12:39 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] 208V/30A/3PH NEMA 3R power distribution question First-time post with an application question after getting guidance from many of you earlier this year about how/where to learn more about safety. So here goes.....I would appreciate recommendations for either reference materials I should read or hardware options to convert a 208V/30A/3PH branch circuit to support qty. 6 of 208V/15A/1PH loads while trying to minimize the hardware volume. Loads do not have internal supplementary protection devices, so I cannot rely on the 30A branch circuit protection w/simple disconnect switch for service support, similar to my home 240V air conditioning compressor circuit. I've searched the PSES archives with a variety of terms (208V, 3 phase, load center, molded case breaker, DIN rail, NEMA, etc.) and have been looking at online (well-known load center/circuit breaker suppliers, electrical supply companies, Mike Holt forums, etc.) and just started calling/visiting local electrical supply companies and big box home improvement stores. Haven't landed on a clear option yet. 3PH load centers all appear rated for 100A or larger capacity requiring larger AWG supply conductors than what I am told the branch circuit will have (10AWG or possibly 8AWG depending on final building construction plans). Descriptions of DIN Rail circuit breakers/supplementary protection devices sounded promising for the smaller form factors, but I haven't found a source that puts all of the hardware pieces together (supplementary protection devices, DIN rails, housing, etc.) into a system that meets NEC requirements -- this doesn't look like a common configuration. I also looked at suppliers of rack mount PDU gear and found one option that is about the size of a 12 circuit load center, but doesn't have a NEMA 3R requirement (surprise..) and would require a larger housing. The 208V PDU's that I have seen and in a couple of cases, peeked inside, have double-pole breakers with C19 outlets rated for 12A continuous load. Are there other options worth investigating or aspects of the power distribution design that I likely am not understanding? Kind regards, Adam - ---------------------------------------------------------------- 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> - ---------------------------------------------------------------- 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>
