Do you have the liberty to share your report - or details and results with the group?
- Robert - Robert A. Macy, PE m...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 101 E San Fernando, Suite 402 San Jose, CA 95112 ----- Original Message ----- From: "Spencer, David H" <david.spen...@usa.xerox.com> To: <emc-p...@majordomo.ieee.org> Sent: Wednesday, October 30, 2002 8:57 AM Subject: RE: Measuring AC Line Impedance > > Follow up............................ > > Having just completed an ton of work on this using input I got around here > (thanks to Don Borowski, Patrick Lawler, Joe Randolph and John Woodgate). > I believe we have characterized the AC mains of our facility. > > As a sanity check/ technical check can any one comment on process. > > Part one > 1)Open circuit voltage measured. > 2)Resistive load placed in circuit. > 3) Voltage drop and current measured. > 4) Voltage drop divided by current provides resistance component of AC > mains. > > Part 2 > 1) Open circuit voltage measured. > 2)Reactive load placed in circuit (approximately 120uF!) > 3) Voltage change (increase really) and current measured (phase angle was > recorded to back check math vectorialy). > 4) Voltage change divided by current provides reactive component of AC > mains. > > > As a side note, I also connected an isolation transformer as the reactive > load, the reactive numbers were very very close. > > The resistive number + reactive number then make up the AC line impedance > for this site: Ztest if you will. > > > > My two remaining questions: > > Is this method of characterizing the AC line impedance valid (is there > something I'm missing)? > > Based on my knowledge of these values, and their ratio to the reference > impedance(s) specified in EN61000-3-3 and EN61000-3-11, I should be able to > calculate and correlate the measured Dmax, Pst, et. al...to the limits > specified in those standards. > (REFERENCE section 6.1.3 of EN61000-3-11), using our existing AC mains. > > > Any comments or input would be welcome. > Thanks > > Regards > David Spencer > Xerox Corp. > > > -----Original Message----- > From: John Woodgate [mailto:j...@jmwa.demon.co.uk] > Sent: Thursday, September 19, 2002 11:56 AM > To: emc-p...@majordomo.ieee.org > Subject: Re: Measuring AC Line Impedance > > > > I read in !emc-pstc that Spencer, David H <david.spen...@usa.xerox.com> > wrote (in <052106A55179D611B34300096BB02E3F8B1D@USAMCMS4>) about > 'Measuring AC Line Impedance' on Thu, 19 Sep 2002: > > >Is anyone familiar with a method to measure and calculate those values. > The > >generic values I have for short circuit condition (which include 4 wires in > >a magnetic conduit) come out higher than my measured values, and those do > >not include the motor generator source. > > Put a large capacitor (mains voltage rated) across the mains and measure > the voltage change; it may actually increase. You need about 50 uF to > get a decent change on 120 V 60 Hz mains. With that result and the one > with the resistive load, you can calculate the source impedance as an R > and L in series. > > I'd be interested to learn the result. > -- > 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...@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" > > ------------------------------------------- > 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" ------------------------------------------- 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"