Dear experts, I hope you can help me with determination of required clearances.
Product is intended for connection to 3P 480V, 60Hz system, OVCIII. After Input EMI filter (with SPD) and rectifier, unit has a resonant circuit which generates high voltages, up to 2300Vpk towards ground (PE). Main standard allowes as an alternative option to use UL840 for spacings. If I go to table 8.1 for required clearances, there in the heading of the table I need to use only supply voltage (phase to ground voltage). So for this particular case required clearance between resonant circuit and internal heat sink connected to ground would be only 3,0mm (phase to ground voltage is <300V). This table completely ignores measured working voltage. Am I on the right track? I think this standard only considered impulse withstand voltage for clearances. Required creepage distance is based on working voltage and this brings high value, however this is not now the concern. Thank you for your support. Best regards Bostjan - ---------------------------------------------------------------- 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>
