Happy New Year! Contrary from what you may have heard, the version of BS EN 60950 available from BSI does include the text of the 4th amendment of IEC 950. I know this because I have a copy on my desk right now.
I believe that the confusion really has little to do with the standards writers, it has more to with the standards publishers (but maybe I'm biased?). In Europe CENELEC (not CEN) try and utilise as much of the IEC text from IEC 950 as possible. Nevertheless, there are some European and National differences between the European standard (EN 60950) and the International standard (IEC 950). Fortunately, the number of differences between EN 60950 and IEC 950 are fewer than the number of differences between UL 1950 / CSA C22.4 No. 950 and IEC 950. In terms of applicability of amendments, the Foreword to EN 60950 explains the effective cut-in dates of the various versions, as agreed by CENELEC. If the European Commission get their way this may change as with EMC standards, but that's another story and is tied in with directives. There are two main ways that you can get copies of ENs: either from CENELEC or from one of the national standards bodies in Europe. ENs are published in three official languages, English, French ad German. BSI publish the official English language version. If you purchase the standard from CELELEC you just get the Common Modifications (applicable throughout Europe) and A Deviations + Special National Conditions (applicable in certain countries only) and then you must cross-refere to the IEC base standard for the remaining requirements. If you purchase one of the official language versions you get the whole text; IEC base requirements (as changed by the Common Modifications), A Deviations and Special National Conditions - what you don't get is the few bits of the IEC standard that were changed by the Common Modifications (although they are marked) and you only get it in one language. Generally speaking, the 'bits' of the organisation responsible for standards writing are separate from the 'bits' of the organisation responsible for publishing the standard. Although the text of the 4th amendment of EN 60950 has been agreed for some time, BSI publishing do seem to have made rather a pigs ear at getting it published. Whether this is true of VDE (who publish the official German language version) I don't know. To add insult to injury, BSI have recently published Amendment 5 to EN 60950. This is Amendment No 9831 and it amends clauses 2.7.1, 2.7.2, 4.3.12 and Annex ZA. Hopefully things have now settled down until the 3rd edition of IEC 950 is published - then you'll really know what being confused means! Well, I guess I've upset enough people at BSI Publishing by now so its time to sign off. Regards, Richard Hughes
