Not sure I understand the concern. The dc/50/60/400 Hz impedance is sub-milliohm, and likewise for power line harmonic leakage currents. Ditto if a fault occurs.
Ken Javor Phone: (256) 650-5261 > From: John Woodgate <jmw1...@btinternet.com> > Reply-To: John Woodgate <jmw1...@btinternet.com> > Date: Tue, 14 Jun 2016 15:39:55 +0100 > To: <EMC-PSTC@LISTSERV.IEEE.ORG> > Subject: Re: [PSES] Screened room mains filter > > Where do you connect the ground wire of the internal screen? > > If the two screens are not connected closely together, voltages exist > between them. The reason the external connection should not penetrate the > wall is so that VHF (and above) signals are confined to the outer surface by > skin effect. > > I still think that putting a filter in the PEC is worthwhile, because it is > likely to minimise any RF voltages at the ground point, which has inductance > to the building ground even with a bonding wire, however thick. > > With best wishes DESIGN IT IN! OOO Own Opinions Only > www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England > > > -----Original Message----- > From: Ken Javor [mailto:ken.ja...@emccompliance.com] > Sent: Tuesday, June 14, 2016 2:52 PM > To: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: [PSES] Screened room mains filter > > Agree with all of Gert's message except the one that contradicts mine: the > internal green wire connection should not be the same as the external, and > the external connection should not penetrate the chamber wall. Either of > these practices will degrade chamber shielding effectiveness, and neither is > either necessary or desirable. > > Ken Javor > Phone: (256) 650-5261 > > >> From: "ce-test, qualified testing bv - Gert Gremmen" >> <g.grem...@cetest.nl> >> Reply-To: "ce-test, qualified testing bv - Gert Gremmen" >> <g.grem...@cetest.nl> >> Date: Tue, 14 Jun 2016 10:34:29 +0200 >> To: <EMC-PSTC@LISTSERV.IEEE.ORG> >> Conversation: Screened room mains filter >> Subject: Re: [PSES] Screened room mains filter >> >> Hi Ian, >> >> Indeed a 2-phase is enough. Ground goes directly to the chambers >> ground-bolt, close to the filter. I recommend installing an extra >> (redundant) separate 4mm2 or larger solid ground bonding connector to >> your buildings main ground, as the leakage current for official >> room-filters may easily exceed 1 A (> 1000 mA), and the infamous >> "single fault" won't be lethal then. >> >> >> Same goes for the internal (in the screened room) ground, it's best >> connected to same bolt as the outside ground. >> >> Most filter have internal discharge resistors, but it cannot be said >> enough verify that the internal capacitors are discharged before >> servicing, or mount your own discharge resistor in the circuit. >> >> >> I suppose this is well known on this list but: >> Note that any grounding is irrelevant for the screening properties. >> >> Regards, >> >> Ing. Gert Gremmen >> Approvals manager >> ---------------------------------------------------------------------- >> -------- >> ------ >> >> >> + ce marking of electrical/electronic equipment Independent >> + Consultancy Services Compliance Testing and Design for CE marking >> according to EC-directives: >> - Electro Magnetic Compatibility 2004/108/EC >> - Electrical Safety 2006/95/EC >> - Medical Devices 93/42/EC >> - Radio & Telecommunication Terminal Equipment 99/5/EC >> + Improvement of Product Quality and Reliability testing Education >> >> Web: www.cetest.nl (English) >> Phone : +31 10 415 24 26 >> ------------------------------------------------------------------- >> This e-mail and any attachments thereto may contain information that >> is confidential and/or protected by intellectual property rights and >> are intended for the sole use of the recipient(s) named above. >> Any use of the information contained herein (including, but not >> limited to, total or partial reproduction, communication or >> distribution in any form) by persons other than the designated >> recipient(s) is prohibited. If you have received this e-mail in error, >> please notify the sender either by telephone or by e-mail and delete >> the material from any computer. >> Thank you for your co-operation. >> >> From: McBurney, Ian [mailto:ian.mcbur...@allen-heath.com] >> Sent: Monday 13 June 2016 15:00 >> To: EMC-PSTC@LISTSERV.IEEE.ORG >> Subject: [PSES] Screened room mains filter >> >> Dear colleagues >> >> I am looking into purchasing a single phase 50/60Hz ac mains input >> filter for a screened room. >> However; I am not sure whether to purchase a 2 line multistage filter >> or a 3 line. >> I'm assuming the filtering is only required on the live and neutral >> lines as the earth should be bonded to the screened room. >> >> Your advice will be appreciated. >> >> Many thanks in advance. >> >> Ian McBurney >> Design & Compliance Engineer. >> >> Allen & Heath Ltd. >> Kernick Industrial Estate, >> Penryn, Cornwall. TR10 9LU. UK >> T: 01326 372070 >> E: ian.mcbur...@allen-heath.com >> >> >> Allen & Heath Ltd is a registered business in England and Wales, >> Company >> number: 4163451. Any views expressed in this email are those of the >> individual and not necessarily those of the company. >> - >> ---------------------------------------------------------------- >> 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) >> 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> > > - > ---------------------------------------------------------------- > 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) 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>
