Re: Hipot requirements 4 TNV circuits
Hi George, After posting a similar question to Treg about a year or more ago, and doing some research, I maximized the spacings and incorporated them into the design practices at a former company. I believe these spacings will carry your product to just about anywhere in the world (which was my intention) you may wish to market. Basic: 3 mm Supplementary : 6 mm Inner layer:0.5 mm Regards, Doug McKean At 09:00 AM 7/1/99 -0400, sparaci...@andovercontrols.com wrote: > >Hello Once Again .. Everyone, > > 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. - 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
George, Do you have transient voltage surge supressors. Maybe this is why you failed the hipot. The standard allows you to pass the Impulse Test in lieu of hipot. Try this method. Regarding insulation between TNV-3 and SELV/Earth the standard allows you the following alternatives routes to compliance: Min. Basic insulation (clearance/creepage) and the 6.4.1 tests (hipot or impulse). Installation by qualified personnel, permanent connection to earth instructions and the tests of 6.2.1.3 (surge test). However, please note that prior to the surge test, anything less than basic insulation on the board is shorted. 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. Hope this helps a little. Read your standard. You will find a statement which says "other solutions are possible". Therefore, you must discuss your problem with your friendly test lab. Best Regards, > > Hello Once Again .. Everyone, > > 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). > > PETER S. MERGUERIAN MANAGING DIRECTOR PRODUCT TESTING DIVISION I.T.L. (PRODUCT TESTING) LTD. HACHAROSHET 26, P.O.B. 211 OR YEHUDA 60251, ISRAEL TEL: 972-3-5339022 FAX: 972-3-5339019 E-MAIL: pe...@itl.co.il Visit our Website: http://www.itl.co.il - 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: RE: EU Official Languages
Bill, What you have said does not actually contradict my own statement (and maybe that wasn't your intention!). One must not confuse the requirement to draw the instructions up in one of the languages of the EU with that of then translating the instructions into the other languages for each territory in which the product is sold. Annex 1 section 1.7.4b of the Machinery Directive says: "The instructions must be drawn up in one of the Community languages by the manufacturer or his authorised representative established in the Community. On being put into service, all machinery must be accompanied by a translation of the instructions in the language or languages of the country in which the machinery is to be used and by the instructions in the original language. This translation must be done either by the manufacturer or his authorised representative established in the Community or by the person introducing the machinery into the language area in question. By way of derogation from this requirement, the maintenance instructions for use by specialised personnel employed by the manufacturer or his authorised representative established in the Community may be drawn up in only one of the Community languages understood by that personnel." What the directive is trying to achieve is a process whereby a complete and coherent set of instructions are created in a community language, and then are translated to be comprehensible to people in states with other languages. You only need one Declaration of Conformity, and this must be in the language in which the instructions were originally drafted. However, this does not mean that you only need to provide the user instructions in one language - it is very clear that every territory which has a different language will require the instructions to be translated accordingly. Quite what the EC hoped to achieve by requiring the instructions to be originally drafted in a community language is not made clear. I would guess the idea was that the structure and culture of the western European languages are sufficiently similar that so long as the instructions make good sense in one of them, they will still be useable in other languages even if they 'loose a bit' in translation. However, if one were to start from (for instance) a coherent document in Chinese, and translate to English one might end up with a document which was pretty well useless unless it's carefully re-written after translation. Regards Nick. At 09:29 -0400 1/7/99, Bill Somerfield wrote: >Please check the following : >Annex II of the Machinery Directive > A. Contents of the EC Declaration of conformity (1) > >(1) This declaration must be drawn up in the same language as the >instructions ( see Annex I, point 1.7.4) and must be either typwritten or >handwrittrn in block capitals. > > > - 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).
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
Re: Hipot requirements 4 TNV circuits
In a message dated 7/1/99, George Sparacino writes: > 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 ? George: The isolation requirements that apply to your modem will differ based upon several variables, including the types of cables attached, how the SELV circuits are grounded, and where the modem is installed. However, in the vast majority of cases (such as a typical box modem) IEC 950 requires "basic" insulation between the TNV3 circuits and the SELV circuits, per clause 6.2.1.2. This translates to 1.0 mm clearance, 1.6 mm creepage, and 1000 VRMS hipot. In my experience, a circuit that provides the required creepage and clearance distances will easily pass the hipot test. You referenced the "950" spec, but did not mention whether you are using UL 1950 or EN 60950. If you are using the second edition of UL 1950, there are some provisions that allow you waive the creepage and clearance requirements and use a simple 1000 VRMS hipot test. The second edition will be withdrawn in April 2000 and replaced with the third edition, which does not allow this option. If your target market includes Europe, you should be aware that Norway and Sweden have taken exception to the requirement for basic insulation that appears in EN 60950, and have inserted national deviations that require supplementary insulation. This requires 2.0 mm clearance, 2.5 mm creepage, and 1500 VRMS hipot. For supplementary insulation, there is an additional requirement for at least 0.4 mm distance through any solid insulation that is used in the barrier. Basic insulation does not have this requirement. If you are looking for a manufacturer's app note on this subject, you might check Midcom at http://www.midcom-inc.com. I seem to recall that they have such an app note. Also, there was a lengthy discussion on this topic about a year ago on the treg listserver. You can search the archives of postings at http://www.rcic.com. Lastly, if you are still confused about this subject, give me a call. If you can describe the specifics of your application, I can quickly identify the applicable clauses in IEC 950 and walk you through the calculation of the requirements for your specific application. 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).
Position open with KeyTek
Having seen numerous postings relating to job openings in EMC, I trust the following is not out of line: Electronic Design Engineer Position Senior electrical/electronic engineer with analog design background to work on design of KeyTek's pulsed-EMI (surge, EFT) and ESD test systems. The ideal candidate would have experience with high-frequency, high voltage, and high current design, and have worked with surge or other pulsed-EMI test equipment. More general relevant design experience would be a background in power electronics, power supply design, or test and measurement instrumentation. Knowledge of the various national and international standards for safety and electromagnetic interference is desirable. This is a senior-level position, and the individual should be degreed with a proven record in product design. In this small company environment there is a great deal of room for professional growth for an appropriate energetic individual. Best Regards Michael Hopkins mhopk...@keytek.com Tel: 1-978-275-0805 ext. 134 Fax: 1-978-275-0850 - 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
Hello Once Again .. Everyone, 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: Safety Incident Reporting
Hi Richard: At one time, The Conference Board put out some very good material about handling safety incidents. I'm not sure it is still available, and I am not sure how to contact them. (They were in the news recently -- they do a lot of stuff!) Best regards from San Diego, Rich - Richard Nute Product Safety Engineer Hewlett-Packard Company Product Regulations Group AiO Division Tel : +1 858 655 3329 16399 West Bernardo Drive FAX : +1 858 655 4979 San Diego, California 92127 e-mail: ri...@sdd.hp.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: Hipot requirements 4 TNV circuits
Hello George: If you fail the high pot test. You should refer to your transformer manufacturer to see if they are IEC950/EN60950 compliant or not. For instance IEC 950 calls for Australian high pot test of 2.5 KV if you have 1.5 KV transformer, then your are more likely susceptible to failure. Also the minimum required distance for creepage clearance for Nordic countries is 2.5 mm while the rest of the world is 1.4 I would suggest look into your art work for the SELF circuit/TNV for meeting these minimum creepage clerance distances. 2.5 mm minimum creepage distance is required as a normal practice to pass the high pot/voltage breakdown test successfully. Best Regards, Nezam Najafi Sr. Compliance Engineer Madge Networks, Inc. -Original Message- From: sparaci...@andovercontrols.com [mailto:sparaci...@andovercontrols.com] Sent: Thursday, July 01, 1999 9:00 AM To: emc-p...@ieee.org Subject: Hipot requirements 4 TNV circuits Hello Once Again .. Everyone, 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). - 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
Certification type documentation such as Declarations of Conformity can be in any EU language. User documentation relating to safe use of the product MUST be in the language(s) of the country in which the product is being sold, although if the product has separate installation or maintainance instructions these can be in a language likely to be understood by appropriately trained personnel. This requirement is a function of the directives (most clearly elucidated in the Machinery Directive, but the principle applies to LVD and EMC, as well as all the other CE mark directives), independently of any requirements contained in harmonised standards. It's a fairly basic principle of criminal law (which this is) that you can't alter your legal obligations by contractual means, so I'm afraid that the basic premise of your approach is flawed. Sorry to say, but you may be living on borrowed time if you are not providing manuals in appropriate languages in all markets. It's also a basic principle of article 100a of the Treaty of Rome (which is the root of all CE-mark directives) that member states of the EU cannot oblige manufacturers of legitimately CE marked goods to meet any different or additional requirements to those laid out in the directives. The requirements of the national public safety law in Germany are required to be harmonised with those of all other EU member states - compliance with any additional requirements (such as any required for the application of certification/agency approval marks) is optional and, in this sense, has nothing to do with CE marking. The effect on your products is as you descibe, but the basis of the requirements is not. Nick. >Richard, > >I can only speak from my experience with the LVD and EMC directives. > >1) The requirement for CE marked products is that the user documentation and >the DoC be in "one" of the official languages of the EU. So, we use English >as one of the languages. > >2) That being said, the safety standards my company uses to comply with the >CE mark, require that we provide user documentation in any of the other >official languages if in fact our customer explicitly requires it by >contract. However this may be a reduced size document containing only those >portions that are specifically related to the safe installation, operation, >maintenance and disposal of the product. It is not required that you >translate sections like theory of operation, applications, sales literature, >etc. > >3) Additionally, when we certify a product through a notified body, in this >case LGA in Nurnberg Germany, the national public safety law requires a >manual in German. I suspect other nationalities within the EU have similar >requirements for certified products. > >This policy has been confirmed by our representative from LGA America. > >-doug > - 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: CANADIAN REQUIREMENTS
Tania, I've interpreted the EMC statement in the Annex of ICES-003 as suggested text only. EMCAB-3 (Issue 3 May 1998) "Implementation and Interpretation of the Interference-Causing Equipment Standard for Digital Apparatus, ICES-003", Q&A #10, says that the ICES-003 regulation is met with either French or English. However, EMCAB-3 goes on further to say in so many words that there may be marketing or other caveats if one of the languages is omitted. For those interested, the EMCAB-3 document can be obtained from: http://strategis.ic.gc.ca/SSG/sf01372e.html#MiscellaneousDocuments Regards, Gary Victorine, Hewlett-Packard Co. gary_victor...@hp.com __ Reply Separator _ Subject: RE: CANADIAN REQUIREMENTS Author: Non-HP-tgrant (tgr...@lucent.com) at HP-ColSprings,mimegw9 List-Post: emc-pstc@listserv.ieee.org Date:6/30/99 1:37 PM Canada requires that these markings be both in English and in French. Here is the exact wording, from Annex of ICES-003 : Canadian EMC statement in English and French: "This Class (insert A or B) digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations." "Cet appareil num/erique de la classe (A ou B) respecte toutes les exigences du R\eglement sur le mat/eriel brouilleur du Canada." (Accent aigue over a vowel is denoted by "/" before that vowel. Accent grave over a vowel is denoted by "\" before that vowel. And both are underlined.) Tania Grant, Lucent Technologies, Octel Messaging Division tgr...@lucent.com -- From: Dale Albright [SMTP:da...@emclabs.com] Sent: Wednesday, June 30, 1999 7:51 AM To: emc-p...@ieee.org Subject: Re: CANADIAN REQUIREMENTS George, It is our understanding that If your equipment meets the appropriate sections of FCC Part 15, than no further testing is necessary for Canadian approval and your FCC report will be acceptable. However, an equipment label is required which is similar to the FCC Class A label. The suggested text is given in the Annex of ICES-003 . "This Class (A or B) digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations." Best Regards, Dale Albright President EMC International, Inc. -Original Message- From: George Waters To: emc-p...@ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Tuesday, June 29, 1999 11:59 AM Subject: CANADIAN REQUIREMENTS > >I need some guidance on an indoor satellite receiver we build. >Functionally it is similar to a DISH network receiver, but ours is not a >consumer product. > >We worked with test labs to obtain conformance to FCC Part 15, and CE, >for which we have a DOC. > >Now our US customer wants to lease some of the units in Canada. What >else do we need to do? > >George Waters > >- >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). - 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).