Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it.
Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!). Once again I ask you - and everyone else in the entire EMC or Safety community world-wide - to read the IEE's guide and let me have constructive comments about how to improve it. You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro (- you only need to download the 'core' document for this exercise and can leave the nine 'industry annexes' for later criticism). I'll make it easy for anyone to comment even if they haven't read the Core of the IEE's guide.... ...the guide is based on the following engineering approach, explicitly stated at the start of its Section 4 and duplicated below. ***** To control EMC correctly for functional safety reasons, hazard and risk assessments must take EM environment, emissions, and immunity into account. The following should be addressed: 1) The EM disturbances, however infrequent, to which the apparatus might be exposed 2) The foreseeable effects of such disturbances on the apparatus 3) How EM disturbances emitted by the apparatus might affect other apparatus (existing or planned)? 4) The foreseeable safety implications of the above mentioned disturbances (what is the severity of the hazard, the scale of the risk, and the appropriate safety integrity level?) 5) The level of confidence required to verify that the above have been fully considered and all necessary actions taken to achieve the desired level of safety ***** Please - anybody and everybody out there - tell me if there is anything wrong with this engineering approach to EMC-related functional safety. Involve experts you know who are not subscribers to emc-pstc too. Please be as detailed as you can be. If I receive no constructive comments about the above 5-point approach by the end of January I will assume that the IEE's guide is on the right tracks and will not need major revisions. You can send any comments to me via emc-pstc or directly to [email protected] or [email protected]. Interestingly, my reading of IEC/TS 61000-1-2 leads me to believe that it follows the same general approach as the IEE's guide. Regards, Keith Armstrong In a message dated 31/12/01 21:58:43 GMT Standard Time, [email protected] writes: > Subj:Re: EMC-related safety issues > Date:31/12/01 21:58:43 GMT Standard Time > From: [email protected] (John Woodgate) > Sender: [email protected] > Reply-to: <A HREF="mailto:[email protected]";>[email protected]</A> > (John Woodgate) > To: [email protected] > > I read in !emc-pstc that [email protected] wrote (in <17c.18c06c2.296 > [email protected]>) about 'EMC-related safety issues', on Mon, 31 Dec 2001: > > > Quite a number of EMC and Safety experts took part in creating the > IEE's > > Guide on EMC and Functional Safety, including a lawyer who specialises > in > > high-tech issues. You will find their names listed at the end of the > 'core' > > of the guide (downloadable from www.iee.org.uk/Policy/Areas/Electro). > Many > > of these experts also involved their colleagues and others so we got a > very > > wide spread of opinion. > > My comments referred to the IEC work, specifically verbal reports from > people involved. You will have noticed that the work culminated in a TS, > not a standard as originally envisaged. That in itself may be an > indication of certain difficulties in its passage through IEC. > > I think that a passionate defence of the IEE document (which I have not > studied, so will not comment on) *may* also be an indication that there > is more emotion surrounding this subject than is desirable. > -- > Regards, John Woodgate, OOO - Own Opinions Only. > http://www.jmwa.demon.co.uk > After swimming across the Hellespont, I felt like a Hero. >
