Re: Surge Test Question
Brian, Seeing higher surge voltages after the mains filter may be due to resonance and the Q of the circuit. In short, the filter might be creating a tuned circuit for the frequencies containted in the surge waveform. Keep in mind that the surge itself could also cause the inductor to saturate, making the model of your RLC tuned circuit have less inductive reactance than you think. One of the best practical explanations I've seen of RLC resonances of and Q is in the ARRL Handbook for Radio Amateurs. Dave __ Reply Separator _ Subject: Surge Test Question Author: brian_ku...@leco.com at INTERNET List-Post: emc-pstc@listserv.ieee.org Date:5/31/2001 11:01 AM When troubleshooting surge problems on products we often see the surge pulse to be much higher after the line filter (testing the AC Mains with Line-Earth surge pulses according to EN61000-4-5). Can someone explain the science behind this and what effect the load might have? Can this increase in the surge potential be anticipated ahead of time so proper clearances can be designed in? Thanks, Brian Kunde LECO Corp. --- 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 Healddavehe...@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://www.rcic.com/ click on Virtual Conference Hall, --- 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 Healddavehe...@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://www.rcic.com/ click on Virtual Conference Hall,
Do not dial 9, 0, #, then hang up when requested.
__ Forward Header __ Subject: Do not dial 9, 0, #, then hang up when requested. Author: cfil...@sears.com at INTERNET List-Post: emc-pstc@listserv.ieee.org Date:3/19/2001 7:44 AM PLEASE READ THE FOLLOWING WARNING FROM IRV LEVINSON: I received a telephone call last evening from an individual identifying himself as an 'ATT Service Technician' who was conducting a test on telephone lines. He stated that to complete the test I should touch nine(9), zero (0), pound (#), and then hang up. Luckily, I was suspicious and refused. Upon contacting the telephone company, I was informed that by pushing 90#, you give the requesting individual full access to your telephone line, which enables them to place long distance calls billed to your home phone number. I was further informed that this scam has been originating from many local jails/prisons. I have also verified this information with UCB Telecom, Pacific Bell, MCI, Bell Atlantic and GTE. Please beware. DO NOT press 9 0 # for ANYONE. The GTE Security Department requested that I share this information with EVERYONE I KNOW. PLEASE pass this on to everyone YOU know. If you have mailing lists and/or newsletters from organizations you are connected with, I encourage you to pass on this information to them, too. After checking with Verizon, they said it was true so do not dial nine (9), zero (0), pound (#) and hang up for anyone! --- 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 Healddavehe...@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://www.rcic.com/ click on Virtual Conference Hall,
Chinese GB/T17626.6-1998 standard
Happy Wednesday, everybody! Is it true that the GB/T17626.6-1998 standard is China's version of IEC61000-4-6? Does anyone know how I can get a copy (in English)? Dave Tarnowski Whirlpool Corporation --- 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 Healddavehe...@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://www.rcic.com/ click on Virtual Conference Hall,
Pacemakers and ANSI standard...?
What is the ANSI standard or regulation for safe limits for people exposed to electromagnetic fields? How about people with pacemakers? I've been informed that there may have been a German study done in 1988 concluding that these field limit values could be used in testing the pacemaker immunity. Can anyone help me to get these ANSI values, at least for the magnetic fields below 400 kHz? David Tarnowski Whirlpool Corp. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
EMC 4343-95
A colleague asked if I knew about the EMC 4343-95 specification. I'd never heard of it. Has anyone out there heard of it and if so, what is it and from where did it come. Dave Tarnowski Whirlpool Corp. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re[2]: Plastic materials for use in Europe?
The only plastic we've had problems with is PVC. FR ABS was not. Dave __ Reply Separator _ Subject: Re:Plastic materials for use in Europe? Author: jim_bac...@mail.monarch.com (Jim Bacher) at INTERNET List-Post: emc-pstc@listserv.ieee.org Date:1/20/2000 8:07 AM posting for Kelly... Jim Reply Separator Subject:Plastic materials for use in Europe? Author: Kelly Tsudama ktsud...@cisco.com List-Post: emc-pstc@listserv.ieee.org Date: 01/19/00 6:21 PM Hi I'm hoping that one of you on this list might be able to help out with regulatory information on plastic materials. What I am trying to determine is what plastic material are allowed to be used in Europe and other parts of the world. For one of our products, we are planning to mold the enclosure from a FR ABS material. This material employs Bromide (sp?) as the flame retardant. I am told that this chemical makes the plastic non-recyclable. I have heard that this is not allowed in some European countries, but can not confirm. Does any one have any experience with this? Thanks in advance for your help!!! Kelly Kelly Tsudama Cisco Systems 408-527-0216 408-525-9150 fax 408-322-9024 pager - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
GFCI suppliers
Does anyone know about how much of the Ground Fault Circuit Interrupt (GFCI) market share each of these companies have? 1. Eagle 2. Arrow Hart 3. Hubble 3a. Bryant (made by Hubble?) 4. Leviton 5. Square D 6. Pass and Seymour Any information will help. David Tarnowski Whirlpool Corp. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re[2]: 60 Hz Power Line Impedance
Ken, My intention was to estimate the charging current going into some capacitors for a motor control board; therefore, my questions was really about getting a design parameter that we could use. The charging current can be high and can damage relay contacts on the motor control board. My colleagues suspect that the US power line impedance is lower, on average, than that of the Euro power lines. Consequently, we'd have to make provisions in the US design vs. the Euro design of this control board. __ Reply Separator _ Subject: Re: 60 Hz Power Line Impedance Author: Ken Javor ken.ja...@emccompliance.com at Internet Date:11/15/1999 1:14 PM Mr. Lacey's final comment is illustrative of what has been my point of view. Why worry about what a specific source impedance is at the line frequency (50/60/400 Hz)? Rather, measure current (steady-state/harmonics/inrush/whatever) while verifying that resultant bus potential (Volts) is negligibly small. In so doing, you verify the maximum current the EUT will generate under any circumstance. Comments? -- From: Lacey,Scott sla...@foxboro.com To: 'david_l_tarnow...@email.whirlpool.com' david_l_tarnow...@email.whirlpool.com Cc: 'emc-p...@ieee.org' emc-p...@ieee.org Subject: RE: 60 Hz Power Line Impedance Date: Mon, Nov 15, 1999, 5:40 AM David, The line impedance will vary considerably with location and type of distribution transformer. The impedance of the secondary will relate to the primary (power utility) impedance as the square of the turns ratio, plus line drops. Your best bet would be to start with inquiries to the power companies and the transformer manufacturers. As to the impedance of a specific power line, the usual method of measurement is to connect a power line qualifier (consisting mainly of a capacitor of known value) to the output of a device which switches at ninety degrees phase angle and measure the inrush current. KeyTek sells a line qualifier for use with their EMC Pro unit. We bought one for power interruption testing, and are gradually having options added. They offer options for surge, EFT, etc. Equipment should always be designed to work over a wide range of line impedance. I once measured 300 amps inrush current at the company facility, and 1200 amps at the power supply vendor's test bench, for the same power supply! Scott Lacey -Original Message- From: david_l_tarnow...@email.whirlpool.com [SMTP:david_l_tarnow...@email.whirlpool.com] Sent: Friday, November 12, 1999 2:32 PM To: emc-p...@majordomo.ieee.org Subject: 60 Hz Power Line Impedance Fellow Networkers; Does there exist information about the impedance (at 60 Hz) of typical power line networks here in the US? In Europe, I know they use a specified reference impedance (at 50 Hz) for flicker testing, which is (0.24 + j0.15) Ohm for line and (0.16 + j0.10) Ohms. This represents, I understand, the European public network impedance as seen at the point of common coupling (i.e., connection to the homes service entrance). David Tarnowski Whirlpool Corporation Global Laundry Controls St. Joseph, MI - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
60 Hz Power Line Impedance
Fellow Networkers; Does there exist information about the impedance (at 60 Hz) of typical power line networks here in the US? In Europe, I know they use a specified reference impedance (at 50 Hz) for flicker testing, which is (0.24 + j0.15) Ohm for line and (0.16 + j0.10) Ohms. This represents, I understand, the European public network impedance as seen at the point of common coupling (i.e., connection to the homes service entrance). David Tarnowski Whirlpool Corporation Global Laundry Controls St. Joseph, MI - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re[2]: Doubt on household equipment interference
Muriel,
I have a couple of questions and comments.
1. Is the video to the TV coming in via cable or antenna?
If you have a good cable coming in and you still get noise, it is more
likely that the noise is entering the chassis via the power cord.
{But, this is not ALWAYS the case as I've experienced when the cable
shield or grounds are not very good}. Putting the blender on the
other phase may help...but I 've never run into this situation and
tried something like you propose. Putting a powerline filter on the
TV is a way to see if EMI is coming in via the power cord.
If you have an antenna feed, the noise could also be radiated from the
long power feeds in your house. In this case, putting the blender on
a different phase will not likely solve the problem.
2. What does the interference pattern on the TV look like?
Are they in the form of vertical, horizontal, or diagonal bars that
roll across the screen?
Vertical or diagonal bars means that the source noise is greater than
the horizontal line-scanning frequency...in conventional TVs this is
15.75 kHz. If you have 10 such lines, your interference frequency is
is at 10 x 15.75 kHz = 157 kHz. This higher this frequency, the more
likely the energy is being radiated off the power line wires in the
wall of your home.
If the noise appears as two very narrow streaks separated by a 1/2
screen and that roll across your screen (as I suspect they would with
interference from brush type motors), your noise source is made up of
random pulses occuring at a rate of 60 Hz. This is broadband in
nature (has some high frequencies in it), so some of this could be
radiated from your home's power grid. Switching the blender to a
different phase will not help much in the case where an antenna is
used.
Dave Tarnowski
Whirlpool Corp.
St. Joseph, MI
Sounds like a definate maybe...
Mike Hopkins
-Original Message-
From: Muriel Bittencourt de Liz [SMTP:mur...@grucad.ufsc.br]
Sent: Wednesday, September 01, 1999 3:55 PM
To: Lista de EMC da IEEE
Subject: Doubt on household equipment interference
Dear Members
I'd like to solve a doubt.. suppose the following:
I have an electrical installation in a house. The feeding is with
three-phase and one neutral conductors. If I connect a TV and a blender
in the same phase, the blender generates interference (lines) in the TV
screen. If I connect the TV in one phase, and the blender in another,
the TV will have interference??? The neutral conductor is the same for
all (of course!)
Seems very plain, but I'd like to know... :)
Thanks in advance
Muriel
--
==
Muriel Bittencourt de Liz
GRUCAD - Conception Analysis of Electromagnetic Devices Group
Federal University of Santa Catarina
PO Box: 476 ZIP: 88040-900 - Florianópolis - SC - BRAZIL
Phone: +55.48.331.9649 - Fax: +55.48.234.3790
e-mail: mur...@grucad.ufsc.br
ICQ#: 9089332
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Re: Transient Surge Suppression
Doug, One of the best resources I've seen on the topic is called PROTECTION OF ELECTRONIC CIRCUITS from OVERVOLTAGES, by Ron Standler (published by John Wiley and Sons, ISBN: 0-471-61121-2. Dave Tarnowski Senior Engnr. Whirlpool Corp. St. Joseph, MI Tel: 616-923-7287 __ Reply Separator _ Subject: Transient Surge Suppression Author: Douglas Best doug.b...@ifrsys.com at Internet List-Post: emc-pstc@listserv.ieee.org Date:8/25/99 10:13 AM Subject: Transient Surge Suppression Mighty Experts of EMC, I have a question concerning the determination of the right Transient Suppressor to use for controlling Lightning Surges. How do I determine the correct size and type of surge suppresser to use (MOV's, Spark Gaps, etc...) to help my power supplies survive the surge requirement of IEC 1000-4-5 to the AC mains? My equipment is all single phase with idle currents below 4 Amps. Any comments or advice would be greatly appreciated. P.S. My questions or comments do not reflect the opinions of my company or their lack of knowledge. :) Douglas BestCompliance Technician IFR America's Inc. Design Engineering RF Division Tel : +1 316 529 5327 10200 W. York St. FAX : +1 316 522 3676 Wichita Ks, 67215 e-mail: doug.b...@ifrsys.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
