Re: E & H Near Field Probes
I am using a probe set (two E-probes and one H-probe) by Com-Power Corporation, based in Southern California. You will also need a pre-amplifier for the E-probes. The one from Com-Power is relatively inexpensive. Their phone number is (949) 587-9800. Regards, Ravinder Email: ajm...@us.ibm.com *** Always do right. This will gratify some people and astonish the rest. Mark Twain Richard Lee on 07/02/99 11:15:19 AM Please respond to Richard Lee To: emc-p...@ieee.org cc: Subject: E & H Near Field Probes Hi Everyone, Can anyone recommend & point me to any manufacturers for E & H field probes of the EMI measurements? Thanks in advance! Best Regards, Richard Lee Richard Lee Adicom Wireless, Inc.Tel: (510) 781-5520x358 26142 Eden Landing road, A-1 Fax:(510) 781-5525 Hayward, California 94545 Title: E & H Near Field Probes Hi Everyone, Can anyone recommend & point me to any manufacturers for E & H field probes of the EMI measurements? Thanks in advance! Best Regards, Richard Lee Richard Lee Adicom Wireless, Inc. Tel: (510) 781-5520x358 26142 Eden Landing road, A-1 Fax:(510) 781-5525 Hayward, California 94545
Re: E & H Near Field Probes
Richard, I have some IFI E-Field probes some with remote display if you want to make an offer Thanks, Derek. - 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).
E & H Near Field Probes
Hi Richard Schaffner-EMC has both RF far-field E & H isotropic probes and near field E & H probe sets. Their EMC-20, used typically for immunity E-field measurements in V/M or W/M squared, measures from 100kHz to 3GHz, with 0.01V/M resolution and can be used stand-alone or via fiber optic. They also make a near field probe set for localizing emissions, if that's your need! Contact Schaffner at Irvine, CA at 800-880-0048 Or visit their Web at www.schaffner.com Wandel & Goltermann also make a large range of Electromagnetic Field measuring probes and I believe Chase Systems markets them in USA at 973-252-660 or www.chasesystems.com Tony O'Hara - 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).
E & H Near Field Probes
Hi Everyone, Can anyone recommend & point me to any manufacturers for E & H field probes of the EMI measurements? Thanks in advance! Best Regards, Richard Lee Richard Lee Adicom Wireless, Inc. Tel: (510) 781-5520x358 26142 Eden Landing road, A-1Fax:(510) 781-5525 Hayward, California 94545
Harmonized Frequency Bands
The R&TTE Directive references harmonized frequency bands for radio equipment. How can one determine if a frequency band has been harmonized for a particular use? My understanding is that it is necessary and sufficient for the appropriate ETSI standard to be published in the OJ under the directive. - 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: Hipot requirements for TNV circuits
In a message dated 7/1/99, Peter Merguerian writes: > By the way, a transformer is not always needed on a modem. The > new design of modems have capacitors (not required to be > Approved) between the TNV-3 and SELV. Hi Peter: It is certainly true that some of the new modem DAA devices use capacitors instead of a transformer (Silicon Labs, Krypton, Conexant, Siemens, Analog Devices, etc). However, I do not agree that the capacitors somehow do not have to be approved. On what basis have you reached this conclusion? There certainly does seem to a debate about what requirements might apply to capacitors used in this application. For basic insulation, some people have argued that as long as the physical size of the cap meets the creepage and clearance, and the cap passes the hipot test, you are all set. My impression is that some safety labs accept this interpretation, while others do not. Sometimes the design goal is to provide supplementary insulation, to comply with requirements in Norway and Sweden. In this case, the isolation requirement includes a minimum distance throgh solid insulation of 0.4 mm. I believe that most multilayer ceramic caps violate this requirement. It is still possible to use such a capacitor by using an approved Y2 cap (per IEC 384-14), but these caps tend to be physically large and somewhat expensive in surface mount. I am aware of a couple of vendors who are trying to get smaller caps approved for bridging supplementary insulation, but I have not heard yet that these efforts have been successful. Do you have more information on this subject? Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (voice) 781-721-0582 (fax) - 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: Follow Up Services/Factory Inspections
Major inspection problems I have encountered. Parts and records problems: * Manufacturer's valid code mark on PCBs not found in the current UL "yellow" book. The mark may be new or just hard to find in the book. * Boxes of harness and cables not marked with appropriate CSA and UL labels. Sometimes this is caused by your own factory removing the parts from the original container and moving them to another box. * Spool of re-spooled wire not UL marked * No certificates from suppliers that molded plastic parts are made with Recognized materials Inspector problems: * Uncertainty of UL inspector on what to look for and what not to look for on "split inspection reports" * Erroneous instructions from European agencies (especially VDE) to local in-country inspectors to also inspect for EMC compliance * Local in-country inspector acting for another agency is unfamiliar with the agency's inspection requirements. This happens all over the world. * Inspectors erroneously asking to inspect hypot pass/fail records Solutions: Most parts problems can be prevented by appropriate incoming inspection procedures. However, when inventory is "dock-to-stock", the best bet is to periodically inspect the parts on the manufacturing floor and inspect the certificates for molded plastic parts. Inspectors must be controlled so they don't inspect an area not under their jurisdiction. You must understand what that jurisdiction is and be forceful if required. Complaining to the agency about an ignorant or rouge inspector is sometimes required. -- From: Jon D. Curtis [SMTP:j...@curtis-straus.com] Sent: Friday, July 02, 1999 8:54 AM To: emc-p...@ieee.org Subject: Follow Up Services/Factory Inspections I am writing an article on preparing for factory inspections. Please share with me your "gotchas" and any advice that a person should know before the inspector arrives. What did the inspector look for? What documents did you need to provide? Any references on what to expect published by the NRTLs or others such as NEMA? Thanks in advance for your comments. -- Jon D. Curtis, PE Curtis-Straus LLC j...@curtis-straus.com Laboratory for EMC, Safety, NEBS, SEMI-S2 and Telecom 527 Great Roadvoice (978) 486-8880 Littleton, MA 01460 fax (978) 486-8828 http://www.curtis-straus.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).
Hipot requirements for TNV circuits - Thank You.
THANKS to all who offered their knowledge to help me with this issue. Have a Fun & Safe 4th of July weekend.. Sincerely, George Sparacino I have a modem product that failed the hipot requirement defined in > > cls 6 of 950. My understanding is that an isolation xfmr between Telco > & > > SELV is needed and clearance from Telco & gnd is to be 3mm minimum. Does > > anyone have any other general design guidelines that they can share on > this > > topic ? > > > > Also, Can anyone point me to any manufacturers app notes for > > components used for telco isolation ? > > > > And if anyone can recommend any reading material, I'd like to read > > up on these and other issues relating to compliance design aspects of > Telco > > circuits. > > > > > > Thanks, > > George > > - 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: 21" rack for Europe
Hello Dwight, There is an ETSI standard which defines the mechanical dimensions and form factor for racking systems housing Telecom equipment within the public network and customer premises, I think this would also apply to your products. ETS 300 119 is a four part standard... ETS 300 119-1: "Equipment Engineering (EE); European telecommunication standard for equipment practice Part 1: Introduction and terminology". ETS 300 119-2: "Equipment Engineering (EE); European telecommunication standard for equipment practice Part 2: Engineering requirements for racks and cabinets". ETS 300 119-3: "Equipment Engineering (EE); European telecommunication standard for equipment practice Part 3: Engineering requirements for miscellaneous racks and cabinets". ETS 300 119-4: "Equipment Engineering (EE); European telecommunication standard for equipment practice Part 4: Engineering requirements for subracks in miscellaneous racks and cabinets". There are different configurations allowed and so I've only copied the text from Part 2, you can freely download the most recent updates of each directly from ETSI (the updates may have been renumbered as ENs so you will also need to search on EN 300 119-x). >From previous experience you'll have to come up with a rack mounting kit arrangement which will cover each of the various rack standards - EIA, NEBS and ETSI if you're building a system for use everywhere. I hope this helps. Best regards, Edward Edward Fitzgerald International Approvals Consultant Direct Tel. : +44 1202 20 09 22 GSM Tel. : +44 4685 33 100 European Technology Services Specialist Global Compliance Consultancy Offices in Australia, Canada and the UK. http://www.ets-tele.com [ Extracted from ETS 300 119-2 - Equipment Engineering (EE); European telecommunication standard for equipment practice Part 2: Engineering requirements for racks and cabinets] 3 Coordination dimensions for racks/cabinets 3.1 Height The height dimension (H) includes covers, feet or castors if these are an integral part of the rack/cabinet structure. For telecommunication centres, H shall be 2 200 mm. For customer sites, H may be at any preferred height, as defined in IEC Publication 917-2 (see Annex B), up to 2 200 mm. Provision shall be made for the possible fitment of height adaptors (for interfacing with overhead structures) as illustrated in Annex A, figure A.1. The racks/cabinets shall also be provided with devices which can be height-adjusted to compensate for any unevenness in the floor. The scope for height adjustment shall be at least 25 mm. The nominal rack/cabinet height shall be measured when the adjustment devices are at their fully retracted positions. 3.2 Width The width dimension (W) includes covers if they are an integral part of the rack/cabinet. W shall be one of four permitted dimensions: 150 mm, 300 mm, 600 mm, or 900 mm. The sides of any rack/cabinet shall not interfere with the assembly of adjacent racks/cabinets (into a straight line-up). The suppliers must ensure that the rack/cabinet will fit into the space between the grid lines, as illustrated in Annex A, figure A.3. Manufacturing tolerances shall therefore be so arranged that this objective will always be achieved, even when racks/cabinets are delivered from different suppliers. NOTE: If additional equipment at the end(s) of a suite of racks/cabinets is required, the associated coordination dimensions shall be specified as an integer multiple of the mounting pitch of 25 mm for each side during equipment practice design and should be agreed between supplier and user. 3.3 Depth The depth dimension (D) includes: a) doors or covers of the rack/cabinet if present; b) all protruding parts e.g. switches, lamps, hinges, locks, electrostatic discharge points, etc.; c) connectors, cabling, cooling fins, etc. For the doors or covers, a minimum reference value for aisle width shall be 750 mm. Doors or covers which are in the open position shall protrude from the front/rear line of racks/cabinets by a maximum of 150 mm. Doors or covers shall be designed so that when open, they do not in any way restrict access to the equipment for essential maintenance and installation operations. D shall be 300 mm or 600 mm. -Original Message- From: Dwight Hunnicutt [mailto:dwight.hunnic...@vina-tech.com] Sent: 01 July 1999 21:46 To: EMC PSTC; TREG Newsgroup Subject: 21" rack for Europe In the U.S., 19" and 23" racks are pretty much the standard (and don't forget the Bellcore hole spacing), yes? How about in Europe? I've heard they use 19" and 21" racks (or their metric equivalent). Is one size typical for data applications, and the other typical to telecom applications? How about hole spacing? -- ___ DWIGHT HUNNICUTT Sr. Compliance Engineer VINA Technologies, Inc. 510-771-3349 520-244-2721 fax www.vina-tech.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, s
Follow Up Services/Factory Inspections
I am writing an article on preparing for factory inspections. Please share with me your "gotchas" and any advice that a person should know before the inspector arrives. What did the inspector look for? What documents did you need to provide? Any references on what to expect published by the NRTLs or others such as NEMA? Thanks in advance for your comments. -- Jon D. Curtis, PE Curtis-Straus LLC j...@curtis-straus.com Laboratory for EMC, Safety, NEBS, SEMI-S2 and Telecom 527 Great Roadvoice (978) 486-8880 Littleton, MA 01460 fax (978) 486-8828 http://www.curtis-straus.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).
RE: NRTL Listing
On Saturday, June 26, 1999 4:30 AM, Finlayson, Joe [SMTP:jfinlay...@nbase-xyplex.com] wrote: > > Hello Group, > > I am in the midst of evaluating the compliance status of a > particular product for a potential OEM relationship. This product is a > standalone box with Ethernet ports powered by an external AC adapter with an > output of 7VDC. The adapter is NRTL Listed, IEC 950 CB report, etc. > although the box itself has no safety certs whatsoever. My understanding is > that there is no legal requirement to have an NRTL Listing, etc. for such a > product although my policy has been to get that third party mark to minimize > liability and such. Can anyone share some more info as to their reasons for > listing or not listing such a product which is well below hazardous limits. Joe, Although devices like these usually seem innocent enoughyou should think about it. For example, under fault conditions, how much current could be supplied by the supplied by the AC adapter. No fire hazard? Burn hazard? Does the box have sharp corners?Contain batteries? If you do rely on an NRTL to set your mind at ease, make sure you get the box approved for use with the specific AC adapter(s) you have in mind. > Horror stories are definitely welcome as I would like ammunition to justify > my case to force the issue. Horror story? No problem. Ask Kodak. or go to http://www.cpsc.gov/cpscpub/prerel/prhtml99/99059.html to see this one: CPSC, Kodak Announce Recall of AC Adapters for Digital Cameras WASHINGTON, D.C. In cooperation with the U.S. Consumer Product Safety Commission (CPSC), Eastman Kodak Company, of Rochester, N.Y., is voluntarily recalling 120,000 AC adapters for use with certain Kodak digital cameras. When the connector plug of the AC adapter is not fully inserted in the camera, the batteries in the camera can overheat to a high temperature. This can cause the batteries to leak acid and explode, possibly causing thermal and chemical burns or lacerations to consumers. Kodak is aware of three reports of the batteries in these cameras overheating and rapidly discharging the battery's contents while using these recalled adapters, including one report of a consumer suffering minor injuries when a battery's content ejected from the camera onto his face and hand. It's clear from the photos that the AC Adapters were approved. I wonder if the Cameras themselves were NRTL tested? Does anyone else know? Matt > > Thx, > > > Joe > > > * > Joe Finlayson > Compliance Engineering Manager > NBase-Xyplex > 295 Foster Street > Littleton, MA 01460 > Tel: +1 (978) 952-5887 > Fax: +1 (978) 952-5054 > Email:jfinlay...@nbase-xyplex.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).
RE: emc compliance
A few tips: RF emission limits are not difficult to meet, once you have knowledge and experience. If a single ferrite suffices to make the design compliant, you are probably not much more then 0-6 dB over limit. Another test house will certainly test a few dB different, you may pass there. (accuracy of EMI test set-ups do not include the test sample and cable setup) Then consider testing another sample. Standard deviation of RF-emissionbetween samples could be large enough to meet the requirements. Possibly you had a worst case sample. 80 % confidentiality interval of your series production should fall within the limits. ( it is possible to reject a batch of all compliant samples if their variation in RF emission is too large: that's statistics) Any clock oscillator in a metal can should be damped using a series resistor. Best thing is to learn how to get your design compliant, and do that. otherwise: Next time, next project, you will (Murphy) probably need 2 ferrites. Ferrites are always more expensive then re-design (on a commercial scale). Commercial end-user products should have the cable delivered with them and have a pre-confectioned ferrite on it. If you tell your customers how to fix the ferrite themselves and why they have to, they will probably leave the ferrite out. Regards, Gert Gremmen Ing. == Ce-test, Qualified testing == Consultants in EMC, Electrical safety and Telecommunication Compliance tests for European standards and ce-marking Member of NEC/IEC voting committee for EMC. Our Web presence: http://www.cetest.nl List of current harmonized standards http://www.cetest.nl/emc-harm.htm 15 great tips for the EMC-designer http://www.cetest.nl/features01.htm -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of lisa_cef...@mksinst.com Sent: vrijdag 25 juni 1999 21:37 To: emc-p...@majordomo.ieee.org Subject:emc compliance Here's a question If you have a product that, at one particular frequency during radiated RF, you simply cannot get to pass the requirements of the relative CE standard without putting an external ferrite on the cable, is it "legal" , to still mark it, provided you inform your customers via the declaration of conformity or in the manual etc., that they could experience problems at such and such frequencies and if they do, to use a ferrite? (boy, that was a mouthful). Faced with a redesign or a statement, the words would be the easier route to take, since in this case, the customer could probably never see the problem frequency range. Comments? thank you for any advise, Lisa - 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).
Re: EU Official Languages
I also wondered... the European Commission publishes the Official Journal of the European Communities in three languages, French, German and English. Why can't we? In a message dated 6/30/99 5:05:05 AM Pacific Daylight Time, s_doug...@ecrm.com writes: << We had several discussions about this issue. I presented to Engineering and Marketing the legal requirements from the directives and let them make the choice as to what languages we should actually use. In the end we decided to print in five languages - English, French, German, Spanish, Italian as a matter of course. Marketing came back with one special request to add either Swedish or Finnish, I can't remember which. We don't do any other languages. We have had no complaints as to what languages we either have or don't have. Except from our documentation people who have to make out the purchase requisitions for the translations which are very costly. Scott s_doug...@ecrm.com -Original Message- From: wo...@sensormatic.com [SMTP:wo...@sensormatic.com] Sent: Tuesday, June 29, 1999 1:44 PM To:emc-p...@majordomo.ieee.org Subject: EU Official Languages When a Directive requires information to be provided to the user, and that equipment is intended to marketed in every EU and EFTA country, what minimal set of languages must be used? I can think of the following languages that are used in these countries. Are there more languages that must be included? Can some of these be deleted? English, French, German, Spanish, Portuguese, Italian, Greek, Dutch, Danish, Swedish, Finnish, and Norwegian (EFTA) >> - 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).
