CSA provides the respective standard's Design Manual for clients that are accredited per their Category Certification program.
Coatings and paint are specifically disallowed per CSA No. 0.4 (which is a requirement per ANSI60950-1), and this standard is the basis of the 40A test. Also, various NEC code articles such as 200,250, and 690 specify materials and construction where being used as any electrical bonding surface. Brian -----Original Message----- From: Kunde, Brian [mailto:brian_ku...@lecotc.com] Sent: Tuesday, March 03, 2015 6:06 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Serrated head screws for grounding/bonding Is there a free on-line reference showing acceptable methods for ground bonding? Screws vs studs? How to properly stack ground bond lugs on to a single stud? Lock washers, star washers, lugs with serrated edges, screws with serrated heads, etc..? Something like this would be most helpful. I recall seeing this kind of information in the back of safety standards we used years ago. BTW, I have reviewed products from several far east companies who use heavy and thick powder coat paint on their products. Then they'll use a screw into a threaded whole for ground bonding without removing the paint. When I bring this to their attention as a possible non-compliance, they reply, "Test It". Sure enough, it will pass a Ground Bond test at 40 amps for 2 minutes. So it is ok as long as it passes the test? The standard we deal with doesn't say anything about surfaces being paint free, cutting through paint, gas-tight, or what type of lock washers to use. It only says, "Screw connections shall be secured against loosening." It doesn't say anything about stacking ground bond lugs on a stud or if you have to use individual nuts between each lug. The Other Brian -----Original Message----- From: Brian Oconnell [mailto:oconne...@tamuracorp.com] Sent: Monday, March 02, 2015 5:10 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Serrated head screws for grounding/bonding The 'star' washer should be gas-tight seal. If a serrated-headed screw is even less of seal, than higher risk-level indicated. Faulty logic? Anyone else observe failure modes of ground-bond hardware? The CSA Design Manuals (not all standards have a respective D.M.) have drawings and specifications for acceptable materials and combinations of ground bond hardware. Recommended. Brian -----Original Message----- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Monday, March 02, 2015 11:47 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Serrated head screws for grounding/bonding In message <blupr02mb1160acb7f7c87a911caabc6c1...@blupr02mb116.namprd02.prod.outlook .com>, dated Mon, 2 Mar 2015, Brian Oconnell <oconne...@tamuracorp.com> writes: >Saw exactly this happen on flight deck of USS Midway during 1979. While >troubleshooting APD10 radar, the hydraulics guy that was helping me >shorted the 400Hz bus to the box containing the power supply, and a >star washer vaporized because part of the converter was floated. The >star washer was not authorized construction. I was talking about serrated-headed screws, not star washers. - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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Thank you. - ---------------------------------------------------------------- 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>
