In message <5d39f9c94199f64fa82e5809c702aa7c01469...@z-160-100-30-229.est.ibm.com>, dated Tue, 26 Aug 2008, "Gordon,Ian" <[email protected]> writes:
> Looking at Table 13 for a DC voltage of between 20 - 30V(inclusive) >the maximum available current is 8A. What does the maximum available >current of 8A as it does not state whether this is 8A average, peak or >rms and also how it is measured, i.e. is it measured with a DMM or >current probe/scope? > >Similarly in UL508C, section 29 Risk of Fire and section 31.4 Limited >voltage/current requirements: in regards to whether a circuit is deemed >to have a "risk of fire", the clause states that the current available >should not exceed 8A. Again is this 8A peak, average or rms and how can >we measure it? In IEC standards, a value of current or voltage is the RMS value, unless otherwise stated. The method of measurement must be one that is sufficiently accurate. This has to be judged on a case-by-case basis, because any generality would be unbearably complicated. +/-1% is sufficient, but may not always be achievable. +/-5% is often quite good enough. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Either we are causing global warming, in which case we may be able to stop it, or natural variation is causing it, and we probably can't stop it. You choose! John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
