Ned, I agree with you except for one point. Most ac/dc convertors are encapsulated. Therefore no internal claearances or creepages. Most likely the external clearance/creepage of 5.0/8.0mm betwen the primary and secondary pins will be met. The IEC 601/UL2601-1 does not have a requirement for oven aging of the potting as in IEC950/UL60950. As such, I would have to say that a 950 ac/dc convertor could pass as long as it meets the stricter leakage current and dielectric strength requirements of the IEC601-1/UL2601-1 standard.
One final comment. Check the UL Conditions of Acceptability for the ac/dc converor and the TUV or VDE license. Most of these convertors specify that the abnormals were tested with a specific type fuse at the input and if any other fuse is used in the end-product, it will be necesary to repeat the abnormal tests. It is very important to use the correct or better fuse characteristics in order to reduce the amount of testing required in the end-product (ie if the convertor manufacturer is willing to share their schematics and providing upotted samples to conduct the tests!). PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 -----Original Message----- From: Ned Devine [mailto:[email protected]] Sent: Thursday, August 30, 2001 3:31 PM To: [email protected] Subject: RE: Medical application-Isolation voltage Hi, The voltages in IEC 60601-1 are rms. See paragraph 20.4.b. You need a converter that is certified for medical. Not only is the dielectric higher, but the spacing (8mm CD, 5mm AC) are higher. Most power supplies designed for IEC 60950 will not pass. Ned Devine Program Manager III Entela, Inc. 3033 Madison Ave. SE Grand Rapids, MI 49548 616 248 9671 Phone 616 574 9752 Fax [email protected] e-mail -----Original Message----- From: John Woodgate [mailto:[email protected]] Sent: Wednesday, August 29, 2001 3:18 PM To: [email protected] Subject: Re: Medical application-Isolation voltage I read in !emc-pstc that Ron <[email protected]> wrote (in <00d501c1309e$f4 [email protected]>) about 'Medical application-Isolation voltage', on Wed, 29 Aug 2001: > >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. Yes, unless another measure is specified. Look carefully: it may be a peak value. > >How does one go about meeting the 4000v test when the highest rated ac-dc >converter I can find is 3500v RMS continuous. > Complain to the converter manufacturers that you can't buy their product because it doesn't meet the standard. It's their problem, not yours! -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Eat mink and be dreary! ------------------------------------------- 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] 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.
