RE: Surge test on a loop
Hello Amund, My guess is that the 20 extra meters of cable allows coupling to be developed between the shield and the conductors contained within. If you do not isolate the one device from the rest of the devices in the loop, is it likely that you are shorting the surge signal to chassis (path of least resistance) without developing the signals on the internal conductors thereby not developing the prescribed signal to the intended device? The set-up figures in the surge standard provide guidance in this regard. Best regards, Don Umbdenstock Sensormatic Electronics Corp Tyco International > -- > From: am...@westin-emission.no[SMTP:am...@westin-emission.no] > Reply To: am...@westin-emission.no > Sent: Wednesday, March 20, 2002 4:58 AM > To: emc-p...@majordomo.ieee.org > Subject: Surge test on a loop > > > Hi all, > > Assume a fire alarm detection system. 10 smoke detectors are connected in > series on a loop and both ends of the loop is connected to the fire alarm > panel. Shielded cable is used and the shield is connected through the > whole > loop. > > So, how do we carry out the surge test on the loop? The alarm panel and > the > detectors are all EUTs. > > As far as I understand IEC61000-4-5:1995 chapter 7.5, I will insert an > extra > 20 meter shielded cable between each detectors and then I will drive the > surge pulse onto the shield in order to test one of the detectors. Then I > move the extra 20m cable to the next detector and surge test it. > > If this is correct, why can't we just put the surge pulse onto the > shielded > loop and assume that the whole loop was tested at once? > > Best regards > Amund Westin, Oslo/Norway > > > > > --- > 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: > Ron Pickard: emc-p...@hypercom.com > 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: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com 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: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
SV: Surge test on a loop
We will apply EN50130-4. It seems that we need an extra 20m shielded cable when testing on of the EUTs. That we swap the 20m to the next EUT. This 20m shielded cable, is it used to obtain capacitive coupling between the shield and the lines ? Amund -Opprinnelig melding- Fra: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av John Woodgate Sendt: 20. mars 2002 15:31 Til: emc-p...@majordomo.ieee.org Emne: Re: Surge test on a loop I read in !emc-pstc that am...@westin-emission.no wrote (in ) about 'Surge test on a loop', on Wed, 20 Mar 2002: >Assume a fire alarm detection system. 10 smoke detectors are connected in >series on a loop and both ends of the loop is connected to the fire alarm >panel. Shielded cable is used and the shield is connected through the whole >loop. > >So, how do we carry out the surge test on the loop? The alarm panel and the >detectors are all EUTs. > >As far as I understand IEC61000-4-5:1995 chapter 7.5, I will insert an extra >20 meter shielded cable between each detectors and then I will drive the >surge pulse onto the shield in order to test one of the detectors. Then I >move the extra 20m cable to the next detector and surge test it. > >If this is correct, why can't we just put the surge pulse onto the shielded >loop and assume that the whole loop was tested at once? You haven't said which product EMC standard you are applying. This matter should have been made clear in that standard. If it isn't, you should press for an amendment to clarify it. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Ron Pickard: emc-p...@hypercom.com 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: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" --- 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: Ron Pickard: emc-p...@hypercom.com 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: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
Re: Surge test on a loop
I read in !emc-pstc that am...@westin-emission.no wrote (in ) about 'Surge test on a loop', on Wed, 20 Mar 2002: >Assume a fire alarm detection system. 10 smoke detectors are connected in >series on a loop and both ends of the loop is connected to the fire alarm >panel. Shielded cable is used and the shield is connected through the whole >loop. > >So, how do we carry out the surge test on the loop? The alarm panel and the >detectors are all EUTs. > >As far as I understand IEC61000-4-5:1995 chapter 7.5, I will insert an extra >20 meter shielded cable between each detectors and then I will drive the >surge pulse onto the shield in order to test one of the detectors. Then I >move the extra 20m cable to the next detector and surge test it. > >If this is correct, why can't we just put the surge pulse onto the shielded >loop and assume that the whole loop was tested at once? You haven't said which product EMC standard you are applying. This matter should have been made clear in that standard. If it isn't, you should press for an amendment to clarify it. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Ron Pickard: emc-p...@hypercom.com 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: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
Re: Surge test on a loop
Amund Westin write: >>If this is correct, why can't we just put the surge pulse onto the shielded loop and assume that the whole loop was tested at once? << I've not done this test. But thinking about it, failure at anything in the loop can prevent the surge from stressing the rest of the EUT's. What if the "wrong one" fails? I don't have the standard here at home, but I suspect you would do as well to test each of the EUT's on a short test loop, alone, that being arguably more severe. Cortland --- 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: Ron Pickard: emc-p...@hypercom.com 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: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
RE: Surge test on a loop
As you say, you have several types of EUTs, and each type must be tested as the EUT. Any other equipment connected to the EUT with cables are considered to be auxiliary equipment. The standard is clear on how to test the EUT when auxiliarly equipment is attached. In your case, the procedure has no knowlege that there is a loop and does not care. All it knowns is that a surge is being applied to a cable. I am sure that there are many ways one could devise to test one or more EUTs at the same time; however, in the end, if you are claiming compliance to a standard, you must test according to the procedure in the standard. If you wish to do otherwise, then you will have to peruse the Technical Construction File route. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: am...@westin-emission.no [mailto:am...@westin-emission.no] Sent: Wednesday, March 20, 2002 4:59 AM To: emc-p...@majordomo.ieee.org Subject: Surge test on a loop Hi all, Assume a fire alarm detection system. 10 smoke detectors are connected in series on a loop and both ends of the loop is connected to the fire alarm panel. Shielded cable is used and the shield is connected through the whole loop. So, how do we carry out the surge test on the loop? The alarm panel and the detectors are all EUTs. As far as I understand IEC61000-4-5:1995 chapter 7.5, I will insert an extra 20 meter shielded cable between each detectors and then I will drive the surge pulse onto the shield in order to test one of the detectors. Then I move the extra 20m cable to the next detector and surge test it. If this is correct, why can't we just put the surge pulse onto the shielded loop and assume that the whole loop was tested at once? Best regards Amund Westin, Oslo/Norway --- This message is from the IEEE EMC Society Product Safety Technical Committee
Surge test on a loop
Hi all, Assume a fire alarm detection system. 10 smoke detectors are connected in series on a loop and both ends of the loop is connected to the fire alarm panel. Shielded cable is used and the shield is connected through the whole loop. So, how do we carry out the surge test on the loop? The alarm panel and the detectors are all EUTs. As far as I understand IEC61000-4-5:1995 chapter 7.5, I will insert an extra 20 meter shielded cable between each detectors and then I will drive the surge pulse onto the shield in order to test one of the detectors. Then I move the extra 20m cable to the next detector and surge test it. If this is correct, why can't we just put the surge pulse onto the shielded loop and assume that the whole loop was tested at once? Best regards Amund Westin, Oslo/Norway --- 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: Ron Pickard: emc-p...@hypercom.com 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: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
