Already thought about that - indicative of the way that my evil little mind tends to function. I wrote the company standard to link the requirements for all abnormal operating conditions specified in the scoped safety standard to the performance requirements and test levels for all immunity tests. But for the purpose of many safety standards, the surge tests that are part of the scoped CISPR standard, are not addressed.
BTW, you should see some of recorded surge levels that were provided by a customer in Australia - who knows what the 'typical' peak and duration of these surges actually are - more w00t for more surge immunity. Brian > -----Original Message----- > From: [email protected] [mailto:[email protected]]On Behalf Of John > Woodgate > Sent: Monday, June 07, 2010 9:02 AM > To: [email protected] > Subject: Re: VDR recommendations > > In message <[email protected]>, > dated Mon, 7 > Jun 2010, Brian O'Connell <[email protected]> writes: > > >There are two parameters here - the max continuous rated > rms voltage > >which is normal operations, and the 'clamping' voltage where the > >component goes low impedance which is abnormal operations. We are > >talking about the former; and the latter is not necessarily > part of any > >safety requirement - other than the component shall not > puke it guts > >out during an abnormal operating condition. > > Depends what you consider as 'abnormal'. For me, spikes on > the mains are > now regarded as 'normal', which is why we fit VDRs. > > The clamping voltage does matter; it must be low enough so that the > clamped voltage doesn't cause downstream damage. Such damage > may or may > not be a safety issue. For example, suppose it damages insulation. > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK > I should be disillusioned, but it's not worth the effort. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
