Hi David, It's good to hear from someone who has spent a couple of second shifts out in the cold 10m test site with me. Hope all is going well.
Your answer would be a possibility for "self-certification" cases. However, if we want to use an NRTL mark such as UL, TUV, CSA ...; then the agency will dictate whether or not to hipot. My understanding is that such agencies will require hipot on products even if they are rated 48VDC (which may be considered SELV) as long as the products use more than a minimum power level. My understanding is that the power level is around 15Watts. I believe that the reasoning behind this has more to do with fire safety than shock safety. Any product that draws more than a certain power level (again I think that about 15 Watts is the cutoff) from a DC mains (i.e. station battery ...) is considered a definite power/energy/fire hazard...thus the hipot requirements. Just a little background...I assume that the test report for this product will specify the testing required; but I wanted to get a feel for what others were doing or would do in the same situation. Chris > -----Original Message----- > From: David Heald [SMTP:davehe...@mediaone.net] > Sent: Tuesday, November 06, 2001 3:08 PM > To: Chris Maxwell > Cc: EMC-PSTC Internet Forum > Subject: Re: HiPot testing of DC mains powered products > > Chris, > Greetings! You may not even need to perform production line hipot > if > the unit is a fiber only product. Since the mains are SELV (unless > you > are shipping to certain Euro Telco's) the only time you should need > production line hipot is if you have wired (TNV-2 or TNV-3) > interfaces, > assuming no other connections to hazardous circuits. > > Granted my advice may be flawed as I am used to permanently connected, > stationary, restricted access location products that are a far cry > from > portable equipment as far as safety standards go. > > Best Regards, > Dave Heald > > > Chris Maxwell wrote: > > > > Hi all, > > > > I have a question. > > > > I have a 48VDC powered product which will be hipot and ground > continuity > > tested off of the production line in order to maintain agency > > certification. > > > > The product uses D-shaped three pin power connector. (Same size as > a > > DB15, but has three large power pins instead of 15 signal pins). > > > > When we sell the unit, we pack it with an accessory kit which > includes a > > 15' cable assembly terminated with the mate to the product's power > > connector. So, essentially, we sell the unit with a "DC mains" > cable > > that we make. > > > > Now, where should the hipot test be performed? > > > > Should I make a test cable assembly for the hipot/ground bond tester > > which is terminated with the proper connector so that the tester can > > plug directly into the chassis? This would essentially test the > chassis > > only. (because we would use this same test cable for every unit) > > > > Or---- > > > > Should I take each unit and connect the DC mains cable to be shipped > > with it, then apply the hipot/ground bond probes to the other end of > the > > DC mains cable? This would test the entire system including the > chassis > > and the cable. > > > > In my mind, this question comes up because we are making a custom > mains > > cable for this DC product. > > > > It is different than AC products; because, with AC products, we can > test > > the chassis by itself and assume that the mains cable is OK because > we > > buy mains cables that have been previously hipot/ground bond tested > by > > their manufacturers. > > > > Any words of wisdom? > > > > Thanks, > > > > 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 | > > > > ------------------------------------------- > > This message is from the IEEE EMC Society Product Safety > > Technical Committee emc-pstc discussion list. > > > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > > > To cancel your subscription, send mail to: > > majord...@ieee.org > > with the single line: > > unsubscribe emc-pstc > > > > For help, send mail to the list administrators: > > Michael Garretson: pstc_ad...@garretson.org > > Dave Heald davehe...@mediaone.net > > > > For policy questions, send mail to: > > Richard Nute: ri...@ieee.org > > Jim Bacher: j.bac...@ieee.org > > > > All emc-pstc postings are archived and searchable on the web at: > > No longer online until our new server is brought online and the > old messages are imported into the new server. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
