Let me add one note to my earlier statement. I must have mixed up clauses. UL 943C exempts special purpose GFCIs from the nuisance tripping requirements of UL 943 section 6.8. However, the conducted immunity section is 6.9 which is still required under UL 943C. I would like to thank Scott Aldous for pointing this out to me.
In regards to John Woodgate's comment, I will state that the UL standard assumes simple motor driven appliances at most and does not take modern electronics into account. Further, because of the locations, it is presumed that no critical loads will be plugged into a GFCI. Appliances such as a refrigerator can have a dedicated outlet that is not GFCI protected. It is presumed that only products with intermittent use will be plugged into a GFCI, and nuisance tripping will be only a nuisance and not a significant problem for the user. I do not know if the Standard Technical Panel has any plans to consider new immunity testing. In contrast, Arc Fault Circuit Interrupters (AFCIs) are required to pass more extensive immunity/nuisance tripping tests. AFCIs are intended to be used everywhere that GFCIs are not used. As such, they will commonly support loads of various types. Nuisance tripping on an AFCI could have more serious consequences if a critical device is plugged into the outlet. I don't have the latest version of UL 1699, but I am aware that AFCI manufacturers are very concerned with nuisance tripping and they test rigorously. I have AFCI breakers for the bedrooms in my house and I have yet to experience any nuisance tripping. Ted Eckert Compliance Engineer Microsoft Corporation [email protected] The opinions expressed are my own and do not necessarily reflect those of my employer. -----Original Message----- From: John Woodgate [mailto:[email protected]] Sent: Tuesday, July 21, 2015 11:46 AM To: [email protected] Subject: Re: [PSES] GFCI Nuisance Tripping In message <cy1pr03mb14704f587f778ae77296424694...@cy1pr03mb1470.namprd03.prod.outlo ok.com>, dated Tue, 21 Jul 2015, Ted Eckert <[email protected]> writes: > The test level is 0.5 V with a frequency range of 150 kHz - 230 MHz. H It's inadequate. Years ago, some European RCDs were found to have a resonance at about 70 kHz and no immunity to speak of at that frequency. But in the world of SMPS and ASDs/VSDs, everything from 50 or 60 Hz to at least 10 MHz is being thrown at the device, and 0.5 V is not enough up to about 10 kHz. Even in Europe, with EN 61000-3-2 and -12 in force, you can get up to 5% THD (8% in some places) on the mains and most of that is usually 5th harmonic. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk When I turn my back on the sun, it's to look for a rainbow John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - ---------------------------------------------------------------- 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]> - ---------------------------------------------------------------- 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]>
