NEW LOCATION FOR THE S.E.E.C FAQ
NEW LOCATION FOR THE S.E.E.C FAQ This is to remind you that, as from today, the new location of the s.e.e.c FAQ Sources of EMC Safety Compliance Information is: http://users.metro2000.net/~purwinc/compliance_faq.htm All those who have bookmarked the previous URL, or maintain a link to it, please amend to the above address immediately. The maintainer and web host is: Charles Purwin purw...@nhinternet.com The Japanese-language version, hosted by Tom Sato vef00...@nifty.ne.jp, will continue at: http://member.nifty.ne.jp/tsato/seec-faq As previously announced the FAQ is now purely web-based and the monthly posting to s.e.e.c has ceased. Regards to all, Bill -- Bill Lyons - b...@lyons.demon.co.uk / w.ly...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EN 61000-3-3
EN 61000-3-3Josh, EN 61000-3-3 only mentions voltage fluctuations and flicker impressed on the public low-voltage system. Inrush current is not specifically measured, although it certainly affects the amount of voltage variation caused by the Equipment Under Test (EUT). To perform the test a controlled impedance (reference network of Fig. 1) is inserted between the ac source and the EUT. The unit is then operated normally while the voltage at the EUT input is monitored. What the test measures is the difference between the source voltage and the EUT input caused by the operation of the EUT. Washing machines and dishwashers may cause particularly nasty flicker because of solenoid valves and motor starting currents. EN 61000-4-11 does mention peak inrush current in regard to qualifying the ac source. The source must be capable of supplying more inrush current then the EUT peak inrush current (30% reserve). However, you would only need to test to EN 61000-4-11 if the appliance had electronic controls (as many do today). Although it may be possible to measure EUT peak inrush current and extrapolate the results, this would not comply with the requirements of EN 61000-3-3. Once the reference network is aquired (or built) the test is pretty straightforward. Best Regards, Scott Lacey Test Engineer (contract) EMC, Safety, Performance Verification -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Joshua Wiseman Sent: Friday, August 31, 2001 2:04 PM To: Emc-Pstc (E-mail) Subject: EN 61000-3-3 Hi all, I have recently heard of a requirement in the Flicker standard for In Rush current measurements. My understanding of the test is that the EUT is manually turned on and off 24 times. During these times dmax is measured. You then take the highest and lowest readings and throw them out. You then average the remaining 22 readings. This has been posed to me from a customer and I can not find any supporting information other than the fact that some test equipment manufacturers are beginning to implement the testing capability in their systems. Any information on this would be greatly appreciated. Thanks in advance for all the help. Regards, Josh
RE: Medical application-Isolation voltage
Ron, You will probably have a hard time finding a converter suitable for this application. Most medical devices are either (if low current draw) battery operated or use a medical grade line-frequency transformer. In the latter case they will also use a medical grade (low leakage) line cord. These have fillers that reduce capacitance between wires. The transformers are often of toroidal construction. Many manufacurers will make these as either 1:1 or stepdown types. Using a 1:1 in front of an ac-dc converter would not be very cost effective. Another possibility may be to use a rechargeable battery with a high isolation relay to switch between charge and operate. You could then use an ac-dc of lower rating to recharge the battery. This is a good compromise for equipment of medium current draw/short patient contact time. Without knowing the particulars of your situation I cannot give more specific advice. Best Regards, Scott Lacey Test Engineer (contract) EMC, Safety, Performance Verification -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Ron Sent: Wednesday, August 29, 2001 11:26 AM To: EMC Subject: Medical application-Isolation voltage I have a medical application that requires double insulation from the Mains to an applied part according to IEC60601. IEC60601 states that for a reference voltage of 250v and double insulation, the test voltage is 4000v for 1 min. I am assuming that the voltages are RMS values. How does one go about meeting the 4000v test when the highest rated ac-dc converter I can find is 3500v RMS continuous. Any help is appreciated. Thanks. Ronald Cyprowski Vascor Inc. 566 Alpha Drive Pittsburgh PA 15238 412-963-7438 x139 r...@vascor.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
