RE: machinery directive related questions
Moshe, If you are having safety related problems at the test site I would recommend that be your first priority not documentation catch up. You may want to try taking an ESD gun to you customer site and run ESD tests on the cables to start with. Try taping a conductor along each cable. Ground one end to the ESD gun and discharge to the other. Use a meter or so of cable. That should show you any cable weaknesses. Next I would kick up the ESD levels at all the other ports and see what's happening. But foremost if you are having trouble in the field I think you need to jump on that immediately. Somebody gets hurt and the only doucmentation you need is a check to the injured party. Just an opinion, mind you. Gary -Original Message- From: mvald...@netvision.net.il [SMTP:mvald...@netvision.net.il] Sent: Monday, November 02, 1998 7:59 PM To: emc-p...@ieee.org Subject:machinery directive related questions Hello Everyone, here are 2 questions: 1. Is Risk/hazard Analysis required as part of formal documentation (TCF?). Which standard defines the format of the analysis? 2. The machine complies with ESD (up to 8KV) immunity, but still I have safety related incidents at customer sites, which are obviously related to ESD (they are simulated at 10KV). What are my options? Should I do nothing? Should I fix the design (up to ?KV)? Should I just document the issue, require antistatic carpets/humidifiers etc from the user? Thanks in advance Moshe Name: moshe valdman E-mail: mvald...@netvision.net.il Phone: 972-52-941200 Telefax: 972-3-5496369 Date: 2/11/98 Time: 19:58:48 You are most welcome to visit my homepage at: http://www.geocities.com/CapeCanaveral/5233/ - 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, j...@gwmail.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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: IEC 320 APPLIANCE COUPLER APPLICATION
One other point. Make sure you know what current you're handling. 8 a and 120 Vac is 960 VA drop that to 30 Vdc and the equipment still needs the power delivered but now your're talking 32 amps. Just an example but it makes a point. Gary -Original Message- From: Robert Johnson [SMTP:robe...@ma.ultranet.com] Sent: Monday, November 02, 1998 7:01 AM To: Stewart, Judd Cc: 'EMC-PST' Subject:Re: IEC 320 APPLIANCE COUPLER APPLICATION There are two concerns about the (mis)use of the connector you discussed. I assume you are talking about the IEC 320 C13 (female, 10A, 70C) and C14 (male), although it probably doesn't matter which IEC 320 connectors you are talking about. Note that there are some 22 different connectors currently and probably more to come. The very first sentence of the IEC 320 standard states that these are for ac only. The first concern is the consequence of plugging a cord into your product which carries (up to) 250 Vac into your 24 volt input. You must assure that should this happen, the product will remain safe (not necessarily still functioning, but safe). The second concern is the consequence of plugging your 24 volt source into a product expecting 120 or 240 Vac. This is a tough one since you don't know the product. It could be a transformer load, in which case you would be likely to overheat and burn out the winding. If you can figure out the consequences of this for all products you are a much better engineer than I. The consequence is that your design is pretty likely to be unsafe under conditions of forseeable misuse, and is in violation of standards in those countries which have adopted the use of IEC standards. I recommend you try something else. Keep in mind it may be reasonable to come up with a hybrid connector useful for combined ac/dc use. For example it is reasonable to have a product which can operate on 40-250 V ac/dc. Such a device would work on 48 Vdc central office supplies as well as typical ac supplies. A modified IEC 320 C13 connector with projections to prevent its use in a normal C14 connector could carry dc into such a product and still meet the above two concerns, while allowing the product to accept normal ac cordsets as well. It also solves the problem of having to guard live unused connections intended for the alternate supply source. Stewart, Judd wrote: Good afternoon everyone, Problem- A universal battery charger that I am reviewing is powered by AC 110-220 or 24VDC. The 24 VDC enters the device via a male IEC 320 connectorOUCH!. The AC enters via a non-detachable recognized power cord with NEMA- 5-15 molded male connector. Commons sense would tell you not to use this connector for the DC but they did...The likely hood that someone would plug AC into it is extremely high. I am looking for a regulation/standard to reference that would prevent this sort of application... any Ideas? Thanks in advance, Judd Stewart 619.623.6639 - 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, j...@gwmail.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, j...@gwmail.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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Polarized Plug; Grounding Type Receptacles
Hi Peter: 1. Can someone explain a polarized plug. A polarized plug (and mating socket) is one which maintains the neutral conductor of the power source through the socket/plug to the product. A polarized plug can be either 2-wire or 2-wire plus grounding. (For the most part, polarization is independent of grounding, although some grounding plug/socket configurations would seem to force polarization.) In North America, all socket-outlets, regardless of voltage or current rating, are polarized. For the 120-V socket-outlet, the building neutral conductor is always connected to the wide hole. (In some older homes, you may find non-polarized -- equal hole size -- 2-wire socket-outlets.) In the U.K., all BS 1363 socket-outlets and plugs are polarized. (This socket/plug requires a ground or a dummy pin to obtain polarization as well as un-shutter the mains connections.) But, in Europe, the Schuko socket-outlet and plug are not polarized. The Australian/New Zealand plug is polarized independent of ground. In North America, polarized plugs are required for any product that has an Edision-base lamp socket. The neutral is required to be connected to the screw shell. Likewise, polarized plugs are required for any product that might otherwise have assymetrical leakage current (e.g., some heating appliances, some motor-driven appliances). (Assymetrical leakage current is where the leakage current differs significantly as a function of the polarity of the connection.) Polarized plugs are also required for any appliance that has an immersion detection device or individual appliance leakage interrupter. 2. Does a product with such a plug considered equivalent protection (against risk of elecric shock) to a grounded (earthed) product or a double-insulated product? Absolutely not! Polarization is very limited as a scheme for protection against electric shock. As mentioned, it principally applies to Edison-base lamp sockets, and to assymetrical leakage current (so as to minimize leakage current). Polarization implies a 2-wire connection (i.e., no ground connection). This means that accessible metal parts are subject to leakage current. Polarization is a means for minimizing the leakage current, regardless whether double-insulated or not. 3. Can a product for use in bathrooms or laundry room be provided with a polarized plug? Yes. In fact, in the USA, most products for use in bathrooms are 2-wire polarized products (e.g., hair dryers). However, they are also double-insulated or equivalent. Almost all hair dryers are provided with an appliance leakage current interrupter -- which requires polarization for correct safety operation. Most products for use in laundry rooms (especially large appliances) are grounded (e.g., washing machines). However, there is no rule against a 2-wire product, polarized or not. 4. Is a grounding type receptacle readily available in all homes in North America? No! Probably as many as 1/3 of all homes in the USA were built before grounding requirements became effective. Only those older homes that have been remodeled have been upgraded to grounded socket-outlets. (This number is based on several straw polls I have conducted among HP employees here in San Diego.) For this reason, we, HP, build all products for the home with double-insulation or equivalent -- even though the product may include a ground wire (usually for EMC or ESD compliance). Best regards, Rich - Richard Nute Product Safety Engineer Hewlett-Packard Company Product Regulations Group AiO Division Tel : +1 619 655 3329 16399 West Bernardo Drive FAX : +1 619 655 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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Earthing at PWB for UL508 Power Supply
Hi Peter: I'm not an expert in UL 508, and have been only peripherally involved in some product certifications. So, my comments may not be highly accurate. As a general rule, UL almost always allows testing in lieu of constructional requirements. This is specifically stated in the Foreword to every UL standard: D. A product employing materials or having forms of construction differing from those detailed with the requirements of this Standard may be examined and tested according to the intent of the requirements and, if found to be substantially equivalent, may be judged to comply with the Standard. However, under some UL engineers, such testing may be resisted. Usually, this means he doesn't understand the intent of the requirements and cannot come up with a suitable test. Some proposals on your part should soften this attitude. Personally, while I've encountered resistance, I've never been held to construction, and I've always been able to test. But, it usually takes a test proposal from me before it will work. The issue of the PWB being capable of carrying fault currents is not easy. Its a function of cross-sectional area. Often, PWB construction does not adequately control the copper thickness. So, UL is justifiably reluctant to rely on the PWB to carry the fault current. If the product is cord-connected, insist on testing with the power cord and fuse in place. 18 AWG power cords will limit the current to the range of 200 amps due to the wire resistance and contact resistance. This makes it easier for a PWB to pass the test. The UL test is a justifiably tough test. You should be looking at very wide traces to carry the fault current. Before you submit for testing, you should be confident that the PWB will indeed carry the fault current without damage! Best regards, Rich - Richard Nute Product Safety Engineer Hewlett-Packard Company Product Regulations Group AiO Division Tel : +1 619 655 3329 16399 West Bernardo Drive FAX : +1 619 655 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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
NPSS, Inc. 4th Annual Vendors' Night (18 NOV)
Hello all, If you are going to be in the Boston area on 18 NOV, don't miss the Northeast Product Safety Society's 4th Annual Vendors; Night. 40 Tables full of product safety and emc resources. The best show of it's kind in the USA; For full details see our website at: www.safetylink.com/#NPSS Deli-Deluxe Buffet: Free to NPSS members (with reservation), $10.00 in advance to others (with reservation) and $15.00 at the door. Regards, Art Michael, for the committee - 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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
New Argentina Product Requirements
Dear Group: Our company manufactures commercial food equipment designed primarily for 60 Hz applications and is, almost without exception, UL Listed. We also export this equipment to many countries around the world and many times it is modified to work at different voltages and at 50 Hz. The latter versions not being submitted to UL. We've just recently become aware of new product regulations in Argentina which require products to be designed and evaluated to IEC-based standards. Products marked with the CE symbol would seem to meet these new requirements. As few of our products have been designed to the IEC standards, our sales into Argentina will shortly be seriously impacted. Have any of you been involved in these regulations and, if so, how are you dealing with them? Are you aware of any effort to rescind or delay implementation of such? Thanks for any information you can share. Regards, Richard Pittenger Agency Approval Engineer Food Retail QA PMI Food Equipment Group Troy, Ohio Ph: (937)332-2621 Fax:(937)332-3125 e-mail: pitt...@pmifeg.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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: IEC-320 coupler in non-standard use
Greetings, Please note that IEC 950 and all its clones, specifies in Clause 2.3.8, last dashed paragraph: --SELV CIRCUITS shall not use connectors compatible with those specified in IEC 83 or IEC 320. Very straightforward requirement. It doesn't mention or imply any exclusions, so this applies to all SELV circuits. Egon :-) At 10:02 AM 02/11/1998 -0500, you wrote: Greetings! I used to work for Lucent Power Systems which is a MAJOR supplier of DC-powering equipment for telecom systems. We used IEC-320 connectors in some of our products in non-AC roles. For instance: we used them as input connectors to rack-mounted DC-to-DC converters (input: 48Vdc; output: 24Vdc) where the IEC-320 inlet on the converter mated to shelf-mounted mating connector. Because the product is used in a limited-access, trained installation personnel environment, UL accepted this application. VDE also accepted this with the caveat that this system be inside of a cabinet with doors. Admittedly, this is a fairly narrow application, but it does demonstrate some flexibility in the use of these connectors which is acceptable to the regulatory agencies. -Jeff Haney Alcatel __ Egon H. Varju, P.Eng. CSA Pacific Region Tel: 1-604-244-6640 HAVE MODEM - WILL TRAVEL Fax: 1-604-244-6600 E-mail:eva...@csi.com var...@csa.ca e...@varju.bc.ca __ - 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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
machinery directive related questions
Moshe, PSNet to answer your 1st question... The MD specifically calls for a risk assessment of the machine. The drafters of the technical aspects of the MD give this guidance: The manufacturer must therefore identify the hazards associated with his machinery and the corresponding requirements; he alone is in a position to do so. The technical file referred to in Article 8 and Annex VI must include a list of the requirements and the means to meet them... The general principles - which cover all of the areas that must be considered are laid out in EN 60292-1 (was EN 292) Basic concepts, general principles and -2 Technical principles and specifications. The methodologies used are laid out in EN 61050 (was EN 1050) Risk Assessment. The use of Annex 1 of the MD as a guide helps in ensuring that appropriate consideration is given for the usual hazards encountered. I usually use a format where the specific hazards are identified, then they are rated as to probability and severity (which is used to rank order them from the most severe to the least) and, finally, the mitigation applied to each is noted which brings it into conformance with the appropriate requirements. This documentation becomes part of the Technical File. - - - - - Peter E Perkins Principal Product Safety Consultant Tigard, ORe 97281-3427 +1/503/452-1201 phone/fax p.perk...@ieee.org email visit our website: http://ourworld.compuserve.com/homepages/peperkins - - - - - - 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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: New Argentina Product Requirements
Dear Richard, I understand that UL is working on an MOU with Argentina. With that in mind, you might want to contact the Technical Assistance to Exporters office at your UL location. Good Luck, Ray Russell ray_russ...@gastmfg.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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: CAN Bus system
Martin Johnson wrote: Any pointers to good information for EMC related problems on CAN bus systems would be appreciated Ideally looking towards ESD, transient immunity and radiated emissions etc. Martin Martin I am not sure where you are located, but there is a one day seminar on EMC of Software in London, England on 12 November, organised by the IEE. One of the papers will deal with CAN bus insecurities. Details are available from Neil Sharp at the IEE, e-mail nsh...@iee.org.uk If you can't get to the seminar, you can purchase a copy of all the papers from the same source. Best wishes Brian Jones EMC Consultant and Competent Body Signatory +44 1564 773319 Telephone 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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: IEC-320 coupler in non-standard use
Which brings up the question about whether central office DC supplies which in some countries or circumstances run up to 70 volts should be considered SELV circuits. We do not treat the central office supplies as SELV at Motorola. Isolation is provided in switching supplies as with ac mains circuits. Bob Egon H. Varju wrote: Greetings, Please note that IEC 950 and all its clones, specifies in Clause 2.3.8, last dashed paragraph: --SELV CIRCUITS shall not use connectors compatible with those specified in IEC 83 or IEC 320. Very straightforward requirement. It doesn't mention or imply any exclusions, so this applies to all SELV circuits. Egon :-) At 10:02 AM 02/11/1998 -0500, you wrote: Greetings! I used to work for Lucent Power Systems which is a MAJOR supplier of DC-powering equipment for telecom systems. We used IEC-320 connectors in some of our products in non-AC roles. For instance: we used them as input connectors to rack-mounted DC-to-DC converters (input: 48Vdc; output: 24Vdc) where the IEC-320 inlet on the converter mated to shelf-mounted mating connector. Because the product is used in a limited-access, trained installation personnel environment, UL accepted this application. VDE also accepted this with the caveat that this system be inside of a cabinet with doors. Admittedly, this is a fairly narrow application, but it does demonstrate some flexibility in the use of these connectors which is acceptable to the regulatory agencies. -Jeff Haney Alcatel __ Egon H. Varju, P.Eng. CSA Pacific Region Tel: 1-604-244-6640 HAVE MODEM - WILL TRAVEL Fax: 1-604-244-6600 E-mail:eva...@csi.com var...@csa.ca e...@varju.bc.ca __ - 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, j...@gwmail.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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Location of Bob German
Hello all, I am seeking the whereabouts of Bob German who is (was?) an EMC consultant for Henry Ott Assoc. in the Boulder Colorado area. Any help is appreciated and may be sent directly to my email address. == Doug Powell, Compliance Engineer Advanced Energy Industries, Inc. 1625 Sharp Point Drive m/s 2018 Fort Collins, Colorado 80525 USA Phone: 970-407-6410 eFax: 970-407-5410 email: do...@ftc2.aei.com doug.pow...@aei.com (new address) == - 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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: IEC-320 coupler in non-standard use
Bob, At 01:31 PM 03/11/1998 -0500, you wrote: Which brings up the question about whether central office DC supplies which in some countries or circumstances run up to 70 volts should be considered SELV circuits. No, if they're over 60 V dc, they shouldn't. By definition, SELV must less than or equal to 60 V dc. We do not treat the central office supplies as SELV at Motorola. Isolation is provided in switching supplies as with ac mains circuits. I agree that this is a sound approach. If you provide reinforced insulation from input to output, then it really doesn't matter if the input is SELV or not. But the original question involved a 48 V dc circuit, which could be regarded as SELV, depending on the actual insulation to the output. If so, then IEC 320 connectors are not allowed. On the other hand, if this input is not considered to be SELV, then there is an exception in IEC 950, if the connector is only accessible by service personnel: Clause 4.3.17:Within a manufacturer's unit or system, plugs and sockets likely to be used by the OPERATOR or by SERVICE PERSONNEL shall not be employed in a manner likely to create a hazard due to mismating. Keying, location or, in the case of connectors accessible only to SERVICE PERSONNEL, clear marking are permitted to meet the requirement. Please note, however, that IEC 320 connectors are clearly specified as being intended for ac applications only. Clause 4.3.17 may be used as an excuse, but it's still basically a poor design. I would strongly *recommend* another connector. Regards, Egon __ Egon H. Varju, P.Eng. CSA Pacific Region Tel: 1-604-244-6640 HAVE MODEM - WILL TRAVEL Fax: 1-604-244-6600 E-mail:eva...@csi.com var...@csa.ca e...@varju.bc.ca __ - 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, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
