Hi John,
Sorry I was away on Friday, I've passed the question on to the customer. What's the significance of 153 degrees? Thanks James From: John Woodgate [mailto:j...@woodjohn.uk] Sent: 16 October 2017 14:56 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] IEC 61000-3-2 Confusion Hello, James. Could you please answer the question below? John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> Rayleigh, Essex UK On 2017-10-12 20:47, John Woodgate wrote: I am bound to be asked another question. Why have a 3 kW heater if it's always used with triac control at a firing angle of 153 degrees or higher? Is it to get very rapid warm-up at full power, then maintaining temperature will much reduced power? John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> Rayleigh, Essex UK On 2017-10-11 17:08, James Pawson (U3C) wrote: Hello John, It uses phase angle control hence the concern about the harmonics generated. Manufacturer specs are single phase, 230V nominal, 3kW. Typically used at less than a 15% duty cycle, often less, in an industrial environment or powered from a generator. My *feeling* is that should be classified as professional equipment and exempted under Clause 7 but the IEV has 0 search for feelings. Thanks for your help James From: John Woodgate [mailto:j...@woodjohn.uk] Sent: 11 October 2017 16:49 To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: Re: [PSES] IEC 61000-3-2 Confusion I agree that there appears to be a need for clarification, and I will take that up with the committee responsible. But for your particular case, what is critical is the nature of the 'triac control'. Is it phase-angle control, or 'burst firing' or something else? John Woodgate OOO-Own Opinions Only J M Woodgate and Associates www.woodjohn.uk <http://www.woodjohn.uk> Rayleigh, Essex UK On 2017-10-11 15:01, James Pawson (U3C) wrote: 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 <mailto: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) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org <mailto:sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org <mailto:mcantw...@ieee.org> > For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org <mailto:j.bac...@ieee.org> > David Heald <dhe...@gmail.com <mailto:dhe...@gmail.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 <emc-p...@ieee.org <mailto: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) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org <mailto:sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org <mailto:mcantw...@ieee.org> > For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org <mailto:j.bac...@ieee.org> > David Heald <dhe...@gmail.com <mailto:dhe...@gmail.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 <emc-p...@ieee.org <mailto: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) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org <mailto:sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org <mailto:mcantw...@ieee.org> > For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org <mailto:j.bac...@ieee.org> > David Heald <dhe...@gmail.com <mailto:dhe...@gmail.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 <emc-p...@ieee.org <mailto: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) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org <mailto:sdoug...@ieee.org> > Mike Cantwell <mcantw...@ieee.org <mailto:mcantw...@ieee.org> > For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org <mailto:j.bac...@ieee.org> > David Heald <dhe...@gmail.com <mailto:dhe...@gmail.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 <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>
