Season's Greetings: I have just reviewed the two "versions" (IEC vs. EN) of "A4" to 950 that we received recently, and I'm confused.
As outlined in the attached e-mail below, A4 is extensive, and modifies most of the pages in the standard. What we really need is a complete, stand-alone EN60950 incorporating all amendments up to and including the IEC's A4 stuff. I am now in doubt whether this exists! Here's what we ordered and received: We ordered IEC950 A4 and received an inch-thick set of replacement pages that need to be inserted into an existing copy of IEC950 (1991). What we thought we were getting was a stand-alone completely updated IEC standard. Oh well. We also ordered EN60950/A4, formally titled "Safety of information technology equipment (IEC950:1991/A4:1996, modified)". This document is only 15 pages long, contains only a few revisions (primarily some "common modifications" and new/revised annexes ZA, ZB, ZC, and ZD), and is meant to be used with EN60950:1992 and its previous amendments A1, A2, and A3. Its content in no way resembles the list of changes below. Am I incorrect in expecting the EN's A4 to implement the IEC's A4, or is the EN's A4 unrelated, and the EN version of the IEC's A4 is still to come? Can someone please explain what's going on here, and point us to a source for a complete, stand-alone EN60950 incorporating the IEC's A4 amendment? Thanks, Jim Eichner Statpower Technologies Corporation [email protected] The opinions expressed are those of my invisible friend who really exists (honest)! Original Message----- From: robertj@anetMHS (Robert Johnson){MHS:[email protected]} Sent: Saturday, June 21, 1997 10:29 PM To: mvaldman@anetMHS{MHS:[email protected]}; JEichner; bceresne Cc: emc-pstc@anetMHS{MHS:[email protected]} Subject: EN60950 amendment 4 content [email protected] wrote: >... as we know, IEC950 amendment 4 is out for some >time. Can someone please send a note of the changes >(DELTA) it contains relative to the previous version? Fourth amendment changes include Voltage measurement Component compliance criteria Restricted access locations Operator and service access Introduction of TNV-1, -2 and -3 circuits Extensive changes to TNV circuit criteria and testing Integration of SELV and TNV requirements Titling of all clauses Enhancement of compliance statements Changes to clearance and insulation requirements New labeling requirements Insulated winding wire criteria Improved criteria for operational insulation and fault testing Error correction and editing Many other changes to clarify interpretations, correct wording or cover new constructions. The amendment is extensive and complex. Over half the pages have been modified. So the message is, don't try to guess its impact from a list like the above. The amendment is available from IEC and from national agencies like ANSI. Get a copy and do an evaluation that meets your own needs. The modifications are margin marked. No brief description would be compelete enough to cover your needs and I can't quote the entire amendment. You need to consider the actual wording in relation to your product to assess its impact.
