Nick, I tend to agree with you. The maintaining an up-to-date file of standards from the view point of a test house gets to be a nightmare.
-----Original Message----- From: Nick Williams <[email protected]> To: [email protected] <[email protected]> List-Post: [email protected] Date: Tuesday, September 28, 1999 10:09 AM Subject: Re: IEC 60990 Vs IEC 60950 > >Very little to do with the topc in the header I'm afraid, but... > >This post raises a point which has concerned me for some time, and which >I'd be interested in opinions from other sources on. > >It is my impression (and it is only an impression - I have made no attempt >to gather objective evidence) that it is increasingly common for new >standards to be issued, and existing standards to be modified, with >certain tests removed from the standard itself and replaced with a cross >reference to another harmonised or IEC standard. > >This seems to be particularly true of mechanical tests (e.g. vibration, >drop test, enclosure access). > >Standards writers would doubtless argue that this makes good sense because >it make updating these specialist requirements easier, and it standardises >(!) the requirements between different documents. > >Personally, it's a practice which annoys me and I think it is bad standard >making. I say this on two grounds: > >1. Few things annoy me more in relation to standards than spending a shed >load of money on an enormous document which is supposed to be a >comprehensive set of requirements and then discovering I have to spend a >load more money to buy subsidiary standards in order to find out what the >requirements of the main standard really are. It's difficult not to >conclude that this is profiteering by the standards publishing bodies. > >2. When you get a test certificate for an appliance which has been tested >to (say) BSEN60950:1992 it would be nice to think you could tell exactly >what requirements have been applied to the product. However, if one has to >know which version of the subsidiary standards have been applied, the >process quickly becomes a nightmare. > >60950 may be a bad choce to illustrate this phenomenon - I'm not very >familiar with it, although I know lots of other people on this list are. >The problem is particularly prevalent in machinery standards, but it is >also creeping into the main electrical safety standards (e.g. EN60204 and >60335). > >Personally I can see no reason not to give the full requirements of the >subsidiary standard in the main standard, and to cross reference the >subsidiary standard as well. That way, when you buy the main standard you >get a completely comprehensive set of requirements, but if you want to see >what might develop you can look at how the subsidiary standards have been >changed since the main standard was last issued. > >I'd be interested in commends from others on this topic - especially anyone >on the list who is closely involved in standards writing. Maybe if enough >people agree with me I could turn this into a comment to be sent to someone >who ought to listen. > >Regards > >Nick. > > > > > >At 12:17 -0400 24/9/99, Peter E. Perkins wrote: >> PSNet >> >> The announcement of the availability of the update to IEC 60990, >>shown below, has been circulating for a short time now. As Convenor >>(Chairman) of this committee I had not generally circulated it to the PSNet >>since it is not a product standard but a basic standard to be used by >>product standards writing committees. As is usually the case, the >>information in basic standards is excerpted or summarized in product >>standards. Two IEC committees have been integrating this information into >>their product standards for some time; IEC TC66/IEC 61010 (and the 1010 >>derivitive EN, CSA and UL standards) and IEC TC74/IEC 60950 (and the 950 >>derivitive EN, CSA and UL standards). The implementation of these >>requirements into these two standards families is done in a slightly >>different way and neither is a full copy of the IEC 60990 set of >>recommended requirements. The certification requirements for the products >>are contained in the end product standard. We expect to see ongoing >>changes to the measurement of touch current at the product level to >>accommodate the introduction of new technology which changes touch current >>and exposes the user to this aspect of electric shock in some new way. If >>you are a designer of test equipment making this measurement or want to see >>the latest information regarding the measurement of touch current you >>should buy a copy of this standard. >> > >--------- >This message is coming from the emc-pstc discussion list. >To cancel your subscription, send mail to [email protected] >with the single line: "unsubscribe emc-pstc" (without the >quotes). For help, send mail to [email protected], >[email protected], [email protected], or >[email protected] (the list administrators). > > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
