Hi all,
Currently helping a customer with a 3-phase power monitoring product to get their electrical safety in order. I understand the requirements for safety isolation from hazardous live/ES3 to user accessible terminals/ES1 based on the possible mains transient voltage of up to 2500Vpk (OVC II). The fundamental question I'm trying to answer is: are there any requirements for safety isolation for the AC supply from phase-to-phase or phase-to-neutral? My understanding is that the requirements are for Functional Insulation only between these lines. Looking at things with my EMC hat on for a moment, we typically conduct Surge tests to IEC 61000-4-5 at 2kV line-to-earth (see above mains transient voltage) but also 1kV line-to-line. Should any functional insulation requirements be based on the working voltage of the phase(s) or the potential line-to-line overvoltage condition of 1kV (or more depending on the environment/OVC)? Referring to IEC 60664-1 I can see that (in table F.4), for a 230/400 3-phase supply, the line-to-line voltage is rationalized to 400Vac. This suggests that line-to-line surges are not taken into account. Are my assumptions correct or am I missing something? Thanks and all the best James James Pawson Unit 3 Compliance Ltd EMC : Environmental : Safety : CE + UKCA : Consultancy <http://www.unit3compliance.co.uk/> www.unit3compliance.co.uk | +44(0)1274 911747 | +44(0)7811 139957 2 Wellington Business Park, New Lane, Bradford, BD4 8AL Registered in England and Wales # 10574298 -- This email has been checked for viruses by AVG. https://www.avg.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 <[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://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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
