I remember testing a device that took a little over 8 hours to run through one cycle of its operation. Their programmer needed 3 days to change each of the operations to as short of cycle as needed to make a measurement or detect a failure. Final cycle time for testing was 6 minutes - it was still a long test.
- Bill Indecision may or may not be the problem. --- On Fri, 11/14/08, Cortland Richmond <[email protected]> wrote: From: Cortland Richmond <[email protected]> Subject: RE: Test setup for equipment operated intermittently To: [email protected] Date: Friday, November 14, 2008, 7:19 AM Hi, Pat. This is another case where prior planning prevents pretty perplexed people (to paraphrase the original). Some years ago. I too was involved with EMC testing of "high-power medical equipment that is used on an intermittent basis." Testing would have taken months and cost millions of dollars had we been restricted to normal operation and duty cycles. The cure for this is, before testing is even begun, to plan on not only enough equipment to test and destroy, but also special firmware and software to ensure that, for EMC testing only, everything that can cause interference, or if testing for susceptibility, problems when it fails to work, runs as close to continuously as can be arranged, even if this is not possible for users themselves as sold. One must of course bear in mind that this could cause the equipment under test to fail by itself, and since we can't have egg in our beer (isn't this forbidden in the EU?) sometimes you'll have to slow down the system so the EUT can survive. Added: It is really cool to see people's lives saved by something one has participated in bringing to market, you know? Cheers, Cortland KA5S ----- Original Message ----- From: <mailto:[email protected]> To: [email protected] Sent: 11/13/2008 12:44:58 PM Subject: Test setup for equipment operated intermittently Hi, I need to run EMC tests on a piece of high-power medical equipment that is used on an intermittent basis. The run time is about 15 seconds to 2 minutes on-time, followed by about 10 minutes off-time. This is comparable to typical system usage. This causes problems with EMC testing, since you normally need a longer observation period. 1) The equipment could be operated continuously, but extra cooling would have to added to the test setup, which is not part of a typical system. In the spirit of regulatory intent would this be considered overtesting? 2) Could testing be done at the highest power level that allows continuous operation? What load conditions/test setup are appropriate for an application like this?! Pat Lawler EMC Engineer SL Power Electronics Corp. - ---------------------------------------------------------------- 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 - 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]>
