Re: [PSES] IEC 61000-4-4 test setup for EUT which have casters
On Fri, 24 May 2013 17:24:35 +0100, John Woodgate j...@jmwa.demon.co.uk wrote: It's known that this clause is inadequate and it will be reviewed, but probably not very swiftly. It has been pointed out that the capacitance between the EUT and the ground plane depends on the permittivity of the support, which is not controlled. Thanks both for the responses. Actually, I didn't mind of permittivity of the insulating material so much, which is plastic or rubber wheel of the casters/rollers in this case. However, I mind of the possible ambiguities, such as: o If non conductive roller/casters part of the EUT can be used as the insulating support, how about commonplace casters like this? http://commons.wikimedia.org/wiki/File:Absolex_san.jpg If such casters can still be used as the insulating support, how about machine rollers like these ones, http://www.machineroller.com/ which are mostly metal but surface of the wheels are covered by plastic or rubber? o If such casters/rollers can be used as the insulating support, which position of the rollers/casters should positioned at the specified height of about 0.1m? Top of the caster/roller, or bottom of its metal component? o This standard didn't use the term may about this. However, if it is an option, it would be expected that one laboratory may put an EUT on the GRP without 0.1m support, and other laboratory may put the same EUT on 0.1m support. This will alter the distance between EUT's bottom surface and GRP, and can cause additional inconsistency of the test results between laboratories, I thought. At this time, we would need to put such EUTs on 0.1m insulating support for some other 61000-4-* standards anyway, and I think it would far easier to put such EUTs on 0.1m insulating support as far as possible also for 61000-4-4 testing. Regards, Tom -- Tomonori Sato vef00...@nifty.ne.jp URL: http://homepage3.nifty.com/tsato/ - 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
[PSES] IEC 61000-4-4 test setup for EUT which have casters
Colleagues, Maybe a slightly silly question, but I want to hear your opinions. IEC 61000-4-4:2012 clause 7.3.1 says: Floor standing EUTs ... shall be placed on a ground reference plane and shall be insulated from it by an insulating support with a thickness of (0,1 +/- 0,05) m including non conductive roller/casters (see Figure 11). When testing EUTs which have commonplace casters (caster which has plastic wheel and metal hub and supporting structure) under it, will you treat the casters as part of the required 0.1 m height insulation support, or will you still put the casters on 0.1 m insulating support? In the former case, what if the casters were higher than 0.15 m? In the case of IEC 61000-4-3:2006, it says that Non-conductive rollers may be used as the 0,05 m to 0,15 m support but it also says ... the support shall be bulk non-conducting, rather than an insulating coating on a metallic structure., so I think we should put the casters, which have plastic wheel but metal hub and metal supporting structure so probably not bulk non-conducting, on 0.1 m insulating support in this case. Regards, Tom -- Tomonori Sato vef00...@nifty.ne.jp URL: http://homepage3.nifty.com/tsato/ - 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] IEC 61000-4-4 test setup for EUT which have casters
My first choice would be to test floor standing products sitting 0.1 m above the ground reference plane (GRP) on a support and don't consider the casters. However, some floor standing equipment is very heavy and can be difficult if not dangerous to try and pick up to set it on a 0.1m support. In those cases you just have to do the best you can and document the alternate setup in the test report. Beware that some casters are conductive. Years ago we found out the hard way that black rubber wheels and pads (under feet) can be conductive. So always use an insulator between them and the GRP. What some labs are doing is to take one of their work stations and sink the GRP 0.1m below the floor level with non-conductive materials on top of the GRP to bring the surface level with the rest of the floor in the lab. This would be a dedicated test area for Floor Standing equipment. You just roll the equipment in and test. You still need access to the GRP to bond your CDNs and Burst Test Generator, but this really makes the setup easy. If you cannot sink your GRP, some labs build up an area on top of their GRP and have a ramp to roll floor standing equipment onto. Again, with some large and heavy products this can be dangerous. Have fun. The Other Brian -Original Message- From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of T.Sato Sent: Friday, May 24, 2013 10:12 AM To: emc-p...@ieee.org Subject: IEC 61000-4-4 test setup for EUT which have casters Colleagues, Maybe a slightly silly question, but I want to hear your opinions. IEC 61000-4-4:2012 clause 7.3.1 says: Floor standing EUTs ... shall be placed on a ground reference plane and shall be insulated from it by an insulating support with a thickness of (0,1 +/- 0,05) m including non conductive roller/casters (see Figure 11). When testing EUTs which have commonplace casters (caster which has plastic wheel and metal hub and supporting structure) under it, will you treat the casters as part of the required 0.1 m height insulation support, or will you still put the casters on 0.1 m insulating support? In the former case, what if the casters were higher than 0.15 m? In the case of IEC 61000-4-3:2006, it says that Non-conductive rollers may be used as the 0,05 m to 0,15 m support but it also says ... the support shall be bulk non-conducting, rather than an insulating coating on a metallic structure., so I think we should put the casters, which have plastic wheel but metal hub and metal supporting structure so probably not bulk non-conducting, on 0.1 m insulating support in this case. Regards, Tom -- Tomonori Sato vef00...@nifty.ne.jp URL: http://homepage3.nifty.com/tsato/ - 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
Re: [PSES] IEC 61000-4-4 test setup for EUT which have casters
In message 20130524.231204.219787274.vef00...@nifty.ne.jp, dated Fri, 24 May 2013, T. Sato vef00...@nifty.ne.jp writes: Maybe a slightly silly question, but I want to hear your opinions. IEC 61000-4-4:2012 clause 7.3.1 says: Floor standing EUTs ... shall be placed on a ground reference plane and shall be insulated from it by an insulating support with a thickness of (0,1 +/- 0,05) m including non conductive roller/casters (see Figure 11). It's known that this clause is inadequate and it will be reviewed, but probably not very swiftly. It has been pointed out that the capacitance between the EUT and the ground plane depends on the permittivity of the support, which is not controlled. -- OOO - Own Opinions Only. See www.jmwa.demon.co.uk Why does everything require an odd number of opamps? 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 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://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@radiusnorth.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: dhe...@gmail.com
