Hi folks,
I apologise as I seem to be all take and not much give on this forum at the moment; I'm trying to do a lot of learning very quickly. Someone ask a question about HDMI so that I can feel useful! Today's question is what appears to be a contradiction in IEC 61000-3-2:2014. * The customers equipment is a triac controlled high-power PSU for welding plastic parts together using resistance heater coils * Power is over 1kW and the customer is suggesting that it is "professional equipment" which, according to Clause 7, means that harmonic "limits are not specified in this standard" * Flowchart in Clause 7 says that Clause 6.1 for allowed control methods still applies even to equipment with no limits * Clause 6.1 says symmetrical control methods which produce large low order harmonics (arguably this applies to triac control) that are used to power heating elements (applicable) provided that either input power is less than 200W (it isn't) or the harmonic limits of Table 3 apply * Clause 6.1 also says that symmetrical control for professional equipment is OK provided one of the "above conditions" is fulfilled (which it is, see previous bullet) So we've gone from Clause 7 saying no limits apply to Clause 6 saying that Class D equipment limits apply. However the flowchart in Clause 7 suggests that just by being exempt from Clause 7 limits means it automatically conforms to 61000-3-2 I feel like I'm going in circles. Does anyone have any insight that might help? Much appreciated, James - ---------------------------------------------------------------- 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>