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 <[email protected]> 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 <[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://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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
