In a message dated 3/14/2003, you write:
As I understand it, for 60950, basic insulation is required between TNV-3 circuits and chassis ground, and supplementary insulation for Sweden and Norway. Do capacitors bridging basic and supplementary insulation (i.e. tip and ring to frame ground) have to comply with IEC 60384-14? Hi David: In Annex ZB of EN 60950, Third Edition, Norway and Sweden explicitly call out Y2 caps per EN 132400:1994, which I believe is based on IEC 384-14. Under EN 60950, Second Edition, the situation is less clear and there are some different interpretations in use. I believe that Semko has issued an interpretation that under the Second Edition, Y3 caps can be used if they are subjected to an additional surge test. Some other labs, however, will accept any cap as long as it meets the applicable requirements for creepage, clearance, and hipot. I think the Second Edition will be withdrawn in 2006, so there are a few years still where Y3 caps can be used. Novacap (http://www.novacap.com) sells surface mount versions of both Y2 and Y3 caps. In general, the through-hole ceramic disc versions are much less expensive, since they are manufactured by a large number of companies including some Asian suppliers. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 j...@randolph-telecom.com http://www.randolph-telecom.com
