Hi, Everyone. When we were qualifying burglar alarm motion detectors, we required the ESD test to be performed, even though in normal operation no one would touch the devices. However, we adjusted the pass/fail criteria such that an ESD event causing a momentary alarm signal would not fail the device under test.
The theory was that, if the alarm system was disarmed, any alarm signal would be ignored, just as a detection of the resident moving about the room would be ignored. And if the system were armed, an alarm signal would be desired, whether by motion detection or by an ESD event, perhaps by someone avoiding the detection field and attempting to disable the device. Of course, any ESD event causing the unit to break was clearly a failure. Chuck Burns Manager of Compliance Cubic Transportation Systems, Inc. 5650 Kearny Mesa Road San Diego, CA 92111 Tel.: (858) 627-4562 Fax: (858) 292-9987 chuck.bu...@cubic.com -----Original Message----- From: Chris Maxwell [ mailto:chris.maxw...@nettest.com] Sent: Monday, June 23, 2003 2:10 PM To: richwo...@tycoint.com; emc-p...@majordomo.ieee.org Subject: RE: ESD - not applicable ? I submit my opinion humbly in the light of the group's massive collective knowledge (grovel, grovel). I disagree with your lab. Your customers may not NEED to touch your product; but they COULD touch it. To me, that is "accessible". Why? Because its outer surface could be touched by a number of activities completely unrelated to its operation or maintenance. Yes, the product may be mounted far from the floor. However, there are tall people and there are feather dusters on poles. (I have to take my wife's word for the existence of the latter :-) If the product mounted to the wall, the only surface that I consider inaccessible is the surface against the wall. To me, all of the other outer surfaces would be "accessible". If the product mounts into the ceiling; then I would consider it to only have one accessible surface. That would be the side protruding from the ceiling. Also, what about coupling plane testing? Indirect discharges from the horizontal and vertical coupling planes simulate the effects of a nearby discharge, not just a discharge to the product itself. I don't see any reason to exempt your product from this testing. Of course, if your product is mounted in a locked, grounded, metal cabinet, 2.5m from the floor; then that's a different story! That doesn't sound like the case (no pun intended). Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | > -----Original Message----- > From: richwo...@tycoint.com [SMTP:richwo...@tycoint.com] > Sent: Monday, June 23, 2003 4:05 PM > To: emc-p...@majordomo.ieee.org > Subject: RE: ESD - not applicable ? > > Clause 8.3.1 of EN 61000-4-2 says "The static electricity discharges shall be applied only to such points and surfaces of the EUT which are acessible to personnel during normal usage." And it also says "The application of discharges to any point of the equipment which is assessible only for maintenance purposes, excluding customer's maintenance, is not allowed unless different prescription is given in the dedicated product specification." > > So, unless the product or family spec says otherwise, no testing is required if a product is touched only during maintenance other than customer maintenance. > > Richard Woods > Sensormatic Electronics > Tyco International > > -----Original Message----- > From: Pettit, Ghery [ mailto:ghery.pet...@intel.com] > Sent: Monday, June 23, 2003 2:59 PM > To: am...@westin-emission.no; emc-p...@majordomo.ieee.org > Subject: RE: ESD - not applicable ? > > > > Amund, > > > > CISPR 24 (and EN 55024) provides reasons to not perform various tests, but ESD doesn> '> t have any of these > "> outs> "> . I think you are entirely correct in wanting the test done. Like you, I have seen this to be one of the more applicable immunity tests (along with surge) and we test to higher levels, too. > > > > Did the lab explain how the equipment would be installed, if not touched by human hands? > > > > Ghery S. Pettit > > Intel Corporation > > > > > > -----Original Message----- > From: am...@westin-emission.no [ mailto:am...@westin-emission.no] > Sent: Monday, June 23, 2003 11:29 AM > To: emc-p...@majordomo.ieee.org > Subject: ESD - not applicable ? > > > > ESD has always been in my view, one of the most applicable EMC tests . We tests all our products with higher levels than stated in the standards. > > > > Last week I visited a local test lab and they told me that " ..... you do not need to ESD test your new equipment because it will not be operated (no keys to press) by humans or not accessible for humans (installed minimum 2.5m above the floor level) .....". Well, I was a bit surprised, because you can easily climb up to it and during maintenance you> may touch it. > > > > So, what's your interpretation for ESD and situation where it is not applicable? We'll carry out the ESD test anyway, because I have no intention to discuss this case with a number of world-wide certification bodies. 20 minutes testing and all parts are satisfied ....... if it pass ..... > > > > > > Best regards > > Amund Westin, Oslo / Norway > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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