Dear Group Question about GFCIs (ground fault circuit interrupter devices):
GFCIs are very common in the USA for safety. It basically measures the differential current between PHASE and NEUTRAL. If more than the threshold current, it trips and protects the user that is causing the ground fault. It is not a new component, I think it has been used for several years. As far as I know, the basic requirement for any GFCI is a tripping fault current of 5mA/60Hz. Question: Household appliances are using more electronic circuits with switching frequencies of several kHz, and an attached EMI filter (Y2 caps to the ground). Is there any special requirement for the GFCIs regarding the frequency of the ground current ? The fact is that GFCIs are tested and UL approved for 60Hz only. It does not avoid unwanted trippings caused by the high frequency components produced by switching frequencies. Something that I know is : For the same product (with some kHz circuit), there are GFCIs that trip (unwanted trips) and there are the ones that ignores the high frequency currents. Thanks in advance ! Günter J. Maass - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
