Re: Excluded Installation Revisited
I would agree that the definition is wooly but there are some points that are clear. First, 'excluded installations' are not outside the scope of the UK regulations. They are excluded only from the need to be CE marked and have a DoC as a whole and from the need to meet the requirements of one of the routes to compliance, They do need to meet the protection requirements. You can be prosecuted under the UK regulations for supplying an excluded installation that causes interference. Second, there is no distinction between intallations supplied by one and by multiple manufactures. The distiction is between installations made from general purpose sub-systems and installations made from sub-systems specifically intended for use in such an installation. A industrial jam cooking system built with standard motors, motor controllers, fans, heaters, temperature controllers and motorised valves could count as an excluded installation even if all the electrical parts came from the same manufacturer. Third the installation must be put together at a specific place. I take this to imply a fixed installation assembled on site. If your training system consists of standard computer system parts, computer, monitor, printer etc. cabled together in ways envisaged by the manufacturers of those parts plus your software then I don't think it could be classed as an excluded installation. If each of these parts is individually CE marked, the easy way out is for you to declare for EMC purposes that you are not supplying a system but marketing a bundle of indivdual items of equipment plus some cables plus some software. The last two do not need CE making and the rest are the responsibilities of their respective manufactures. The excluded installation is not the easy way out it first seems except for manufacturers of plant that only exists in its final form on site. Each of the sub-systems must be tested and comply and must have instructions on how it may be integrated in such a way that the installation continues to comply. To be able to give such instructions in confidence it is likely that you would need to test the sub-system in something like its installed configuration. You need to ensure the intallation is assembled according to those instructions and to document the whole installation. These rules apply specifically to the UK implimentation. Although installations are mentioned in the Commission guidelines. I am not aware of them being incorporated in any other national implimentation. They are not in the French or German ones. Nick Rouse
CE Mark
The UK implimentation of the EMC regulations SI 1992 No Si2372 makes it an offence to take into service relevant equipment that does not comply with the essential protection requirements of not causing or being susceptible to interference. There is no specific offence of taking into service equipment that is not CE marked, has not met the requirements of one of the routes to compliance or has not had a declaration of conformity issued. These offences only pertain to the supply of equipment. It might be argued that to knowingly buy non-CE marked equipment makes one an accessary after the fact in the offence of supplying such equipment but I expect that the chances of such a prosecution are vanishingly small. The question you have to ask is how can you be sure that a non-CE marked computer does not actually cause interference. It is most probable that if it did cause interference and it came to the notice of the authorities, you would be told to stop operating the equipment or to fix it but in the case of a large scale user of interfering equipment, the authorities might chose to prosecute especially if there had been prior complaints. In such a prosecution, if you were judged to be sophisticated enough to know about CE marking, the fact that you knowingly took the equipment into service without CE marking may count against you as evidence of reckless disregard of your duty to take due care to avoid taking into sevice equipment that did not meet the protection requirements. Nick Rouse
RE: AC Powerline harmonics
Richard Nute suggests there is a power limit to the effectiveness of a inductor in meeting the harmonic limits. If you are prepared to use multiple inductors and capacitors in a low pass filter configuration between the rectifier and the linear regulator there is no theoretical limit to how much you can suppress harmonics. The limit is the practicality of the use of such filters. You tend to need values of several henries capable of taking the DC current which may be 10's of amps without saturating. Such inductors are large. Nick Rouse
European Power Cords
This question relates to the use and application of power cords provided into the EU when shipped from the USA. A company builds one version of a highly configurable product. The user chooses any combination of optional pwbs (over 20 different options) plugged anywhere into a large backplane along with a choice of several different power supply assemblies (universal auto-voltage detect, redundant, non-redundant, etc.). The product is handled by European distributors who order a large number of units for their warehouses for reshipment to any country within Europe, including non-European countries. The manufacturer, located in the USA, has no idea what country the unit will be sold to or how it is finally configured since this is up to the European distributor to configure and sell the unit. The USA manufacturer provides a North American power cord set as a default item to all shipping assemblies, since most units sold are to North America. The company, at no charge, will provide to the distributor a power cord appropriate to the end country's application. This power cord is purchased from a European power cord manufacturer, located in the UK, and dropped shipped to the distributor, also located in the UK (one of several European distributors throughout the continent). The following issues have now been raised by a sales manager in the UK which we are unable to answer. 1. Is it legal to ship North American, 120VAC power cords into the UK, knowing that these cords will be thrown away upon receipt? Please provide the statutory Instrument in UK law that says 120 VAC rated cords are illegal for importation, even if they will never be used. 2. Please provide the UK statutory Instrument (and any other European Country National Law) that mandates products received from North America must contain a power cord appropriate to their national electric requirements, plug specific. 3. In examining the LVD and EN 60950, no mention is made regarding the legal requirement to ship a particular power cord into Europe. The LVD para 3.2.4 mandates electrical requirements and type of cordage required. 4. If the USA manufacturer cannot stock variations of European power cords, then how does your company handle this issue of multiple power cordsets for use worldwide. 5. Are their any other statutory Instruments or requirements related to power cord usage within the EU not addressed above. Thank you. Mark Montrose ma...@hls.com
Re: IEC 529
Item Subject: IEC 529 Received: from hpcc01.corp.hp.com by hpcc08.corp.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.4 Openmail) id AA056179049; Mon, 20 May 1996 09:17:30 -0700 Received: from relay.hp.com by hpcc01.corp.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA119349046; Mon, 20 May 1996 09:17:27 -0700 Received: from mail.ieee.org (rab.ieee.org) by relay.hp.com with ESMTP (1.37.109.16/15.5+ECS 3.3) id AA142589044; Mon, 20 May 1996 09:17:24 -0700 Received: by mail.ieee.org (8.7.3/8.7.3) id KAA13337 for emc-pstc-list; Mon, 20 May 1996 10:48:56 -0400 (EDT) From: sandy_florence-esf...@email.mot.com List-Post: emc-pstc@listserv.ieee.org Date: 20 May 96 09:46:50 -0500 To: emc-p...@ieee.org (Receipt Notification Requested) Subject: IEC 529 Message-Id: <"Macintosh */PRMD=MOT/ADMD=MOT/C=US/"@MHS> Sender: owner-emc-p...@majordomo.ieee.org Precedence: bulk Reply-To: sandy_florence-esf...@email.mot.com X-Resent-To: Multiple Recipients X-Listname: emc-pstc X-List-Description: Product Safety Tech. Committee, EMC Society X-Info: Help requests to emc-pstc-requ...@majordomo.ieee.org X-Info: [Un]Subscribe requests to majord...@majordomo.ieee.org X-Moderator-Address: emc-pstc-appro...@majordomo.ieee.org ... Item Subject: IEC 529 Hello San, My experience with IP code marking of products has only been with OEM Vacuum Pumps using Electric Motors that were marked with an IP code. However, IP coding was never a concern for products that met IEC 1010-1 as long as the end product met all enclosure requirements of 1010-1. Regards, Ron Wellman well...@corp.hp.com __ Reply Separator _ Subject: IEC 529 Author: Non-HP-owner-emc-pstc (owner-emc-p...@majordomo.ieee.org) at HP-PaloAlto,shargw3 List-Post: emc-pstc@listserv.ieee.org Date:5/20/96 7:46 AM Is anyone familiar with the standard and is it necessary to mark product with the IP code? Regards, San
Low Voltage Directive
Does the Low Voltage Directive apply ? We are a manufacturer of portable, battery powered (NiCd), tele-transaction computers. Typical battery voltage is between 3.6 V and 9 Vdc. All the units have a LCD screen. LCD's with backlight do need a AC voltage of around 100 Vac or more. This voltage is generated internally by a DC-AC converter. The source impedance is that high that it never can be of any danger to the user. The housing is of plastic and there is no way to touch parts of the internal DC-AC converter. Does the Low Voltage Directive apply ? What if a charger is connected to the unit ? Edgard VANGEEL International RF approvals department Telxon Corporation - Brussels email1 : evang...@tornado.be email2 : edg...@telxon.com
EMC / modules
Some of our products (portable ITE) can be equiped with a WAN radio module. The non-radio version of the ITE equipment has already a CE mark. The radio module (oem) is provided with the CE-mark. The radio module will be internal, using the same housing as the ITE equipment. The new combination now is considered as a (Radio) Telecommunications device. Can we affix the CE label without additional testing on the new combination? In other words can we combine individually CE-approved modules without additional testing? Edgard VANGEEL International RF approvals department Telxon Corporation - Brussels email1 : evang...@tornado.be email2 : edg...@telxon.com
Re: Excluded Installation Revisited
Alan, We know what is "excluded" from needing a CE mark: (1) Products for which there are no legal requirements as to their technical characteristics (2) Products for which there only exist national requirements as to their technical characteristics (3) Products for which the requirements as to their technical characteristics are laid down in EC directives "OUTSIDE" the "new approach" Many of the authorities having jurisdiction now feel that we should consider as apparatus only "components of a complex nature" and that simple modular components such as for instance, diodes or integrated circuits, need not comply with the essential requirement, need not be subjected to any conformity assessment practices and need no marking. That, would not exclude your CBT system. The questions I would ask myself are: Are there legal EU requirements as to the technical characteristics of a CBT system ? If so, are they inside or outside directives under the "new approach" ? I suspect that the answer to the first question is NO, thus exempting your CBT system. Please note that this would NOT exempt the components of you CBT system from having to carry the CE marking. Having said that, I am convinced that each part of a system can be as safe as all get-up, but if assembled by somebody not steeped in the arts, may result in a dangerous package. This particularly holds for "distributed systems" such as PBXs, LANs, etc. Regards, Vic
Excluded Installation Revisited
To re-visit a previous theme "what is an excluded installation": 1a. The UK Statutory Instrument, clause 13, answers this with (paraphrased) "two or more items or systems put together at a given place to fulfil a specific objective but not designed by the manufacturer(s) for supply as a single unit". 1b. This seems rather "woolly" to me. 2a. The "sci.engr.electrical.compliance" Newsgroup FAQ has the above definition, but adds "In effect, an excluded installation is a collection of compliant apparatus." 2b. But, it then goes on "Thus a large installation supplied as a single unit is not excluded, where as one supplied by a number of manufacturers is outside the scope of the UK Regulations." 3. Now, we make Computer-based Trainers, where we buy-in "CE marked" computers, add our application software, cable it all up and deliver it as a single CBT system. So we meet the definition of 2a, i.e. it is a collection of compliant apparatus, but we do not meet 2b, as it is supplied as a single unit. Where does this get me - absolutely nowhere! I know of one Competent Body who has said that such a system (a collection of compliant apparatus) _is_ an excluded installation. But the above seems to indicate that his opinion is not universally shared. What do you all think? regards, Alan Hudson EMC/EW Specialist Marconi Simulation (Scotland, UK) email1 hud...@msim.co.uk email2 100534@compuserve.com
Re: IEC 529
Typically and IP code indicates an enclosure rating. I.e. resistance to hose applied water, dirt, dust, dripping water, oil, etc. They are roughly equivelent to Nema type standards. I.e. Nema 4, Nema 4X, Nema 12. Generally the need for this type of rating is dependent upon the environment your product will reside in when installed in the field. Generally, if you are looking at a factory-floor type environment, you would be looking at IP65, which is roughly equivelent to Nema4. In the IP rating, both digits carry significance, for example...in IP65, the 6 indicates a "dust-tight" enclosure, and the 5 indicates protection against water applied through a direct hose jet. Generally the grid looks like this: Digit 1 0 Non Protected 1 Protected against solod objects > than 50 mm 2 Protected against solid objects > than 12 mm 3 Protected against solid objects > than 2.5 mm 4 Protected against solid objects > than 1 mm 5 Dust Protected 6 Dust Tight Digit 2 0 Non Protected 1 Protected against dripping water 2 protected against dripping water when tilted to worse case opening 3 protected against spraying water 4 protected against splashing water 5 protected against water jets 6 protected against heavy seas 7 protected against the effects of immersion 8 protected against submersion These are the enclosure ratings for an ordinary, or non-classified, location. These ratings are different if you are considering an installation into a classified or hazardous type environment. i.e. Class 1 Division 2 (USA) or Zone type environments in Europe! I hope this helps.if you need some more info, please feel free to contact me: Robert L. Terry Nematron Corporation 313 994 0591 Ext 235 robert.te...@nematron.com
Re: IEC 529
Sandy Florence asked whether anybody knew anything about IEC-529 and "do you have to comply with it" You'll have to be a bit less cryptic with that question. IEC-529, is the brainchild of TC70 on Degrees of Protection provided by enclosures (IP Code) and is a basic Safey Publication. TC70 prepares international standards, including appropriate test methods, where those have not been provided in other IEC Publications, for degrees of protection provided by enclosures against ingress of solid foreign objects and water and against access to dangerous parts. That includes standardization of access probes for use in IEC Publications. In as much as the standards you use, invoke IEC Probes, or call for IPs, yes I believe that you will have to comply. According to my information, neither the USA or Canada participates in the work of TC70, but I would be very surprised if my old friend Walter Skuggevik of UL did not track what happens there, just to keep the fickle finger of UL alive and well. In addition, Al Brazauski, now back with UL, headed a taskforce in IEC TC74 that was looking at enclosures. Regards, Vic
Re: CE Mark
Ron Fotino said: "I don't know about the "legal" position. However, it seems to me if you are buying the PC for personal use, there is no risk of losing your PC." Fully agree. If the manufacturer recalls the product, there is no obligation on the part of the buyer to respond to such a recall. I would be very surprised if the "recall" by a small jobber in London, would result in a return of more that 5% of the products he assembled. (I would be very surprised if a small jobber in London would not just disappear and open up under a new name in another section of the city before being put into a position where he/she would have to do a recall). "If you are buying alot of them for corporate use or resale, might I suggest you "leverage" the manufacturer to do the proper testing and make the declaration. You could test them yourself. This is a problem though because the manufacturer could make changes without letting you know." If the assembler is working on a scale where he/she fills corporate orders or delivers for resale, we are no longer talking about a real "SMALL" operation in the first place. In addition, most corporations that buy PCs in bulk do have policies in place (for self protection purposes) that would not allow them to buy stuff that is not properly certified and marked. Ergo, while this is sound advise, I doubt that in real life this advise is needed. It is part of the normal business environment. "It is very realistic to believe that a small PC "manufacturer" would go into liquidation before facing prosecution." I must repeat that in a world where the PC is subject to so many innovations, at so rapid a pace, that much of the assembling, upgrading and integrating will be done by "other than" the original equipment manufacturers, the notion of testing/certifying products as a whole is becoming increasingly anachronistic. I suspect that trying to test/certify/license the assemblers will prove equally anachronic. There are just too many hungry people out there that need to make a living. Collectively, we will have to put on our thinking caps and try and find "do-able" solutions. Regards, Vic Boersma
Re: CE Mark
I don't know about the "legal" position. However, it seems to me if you are buying the PC for personal use, there is no risk of losing your PC. If you are buying alot of them for corporate use or resale, might I suggest you "leverage" the manufacturer to do the proper testing and make the declaration. You could test them yourself. This is a problem though because the manufacturer could make changes without letting you know. It is very realistic to believe that a small PC "manufacturer" would go into liquidation before facing prosecution. Ron Fotino __ Reply Separator _ Subject: CE Mark Author: rgu...@anonymous.com at !INTERNET List-Post: emc-pstc@listserv.ieee.org Date:5/19/96 4:11 AM There are many small PC manufacturers in the UK who are selling systems/equipment which are not CE marked. This is clearly illegal. Can any one suggest what the legal position would be for the purchaser of the goods?. Is there any possibility that if the manufacturer is prosecuted, the goods may be recalled. If the manufacturer then goes into liquidation rather than face the concequences the purchaser may loose their PC. RCIC Guest rgu...@anonymous.com Courtesy of RCIC http://uc.com/compliance_engineering/
RE: AC powerline harmonics
Hi Tony Ref: your response to Jerry Fix's mail.. > I thought power line harmonics from power supplies were > due to the non-sinusoidal waveshapes of the input current > waveforms from switchers. > > Wouldn't a linear power supply create only sinusoidal > waveshapes at the line frequency such that there would > be essentially no harmonics from the input current waveform > (i.e. no special design treatment required for linear designs)? > > At least this would seem to be true to the extent there is no distortion > of the input waveform due to lienar circuitry. The problem with Linear supplies is the charging current of the main smoothing/storage capacitors. In each mains half cycle, the diodes in the main rectifier will only conduct when the instantaneous supply voltage exceeds the capacitor voltage by app. 0.7V. As the capacitor is probably charged up to just about Peak supply volts, the only time this happens is right at the top of the sine wave. This often means that the capacitor must be recharged in something like 1mS if the capacitors are over sized (as they often are). If the supply output is 10A, this means that the rectifier has to provide 100A (10mS/1mS @ 50Hz) for the 1mS right in the middle of the half cycle. This very high current at the peak of the sine wave is the odd harmonic that causes all the problems. It has the effect of squaring the supply sinewave. Cures include placing large inductances in series with the feed to the main smoothing capacitors (remember the 'old fashioned' valve radio supplies and their choke input filters..), reducing the size of the main capacitors (increasing ripple, but reducing harmonics) or using HF non synchronous PWM switched rectifiers with suitable input filtering. A better solution, not available to domestic, light industrial, is to rectify three phase, the resultant output hardly needs any capacitive filtering if regulation is used downline. That should make things as clear as mud... Chris Dupres EMC Specialist. VG Microtech. cdup...@vacgen.fisons.co.uk tel +44 (0) 1825 761077 fax +44 (0) 1825 768343 'Opinions expressed are personal, not necessarily Corporate'
Re: AC powerline harmonics
Jerry Fix asked about an "inexpensive and simple way to control power line harmonics (IEC 555 type) for medium power (500 -1000W) linear power supplies?" Other contributors to this listserver have already pointed out that linear power supplies have exactly the same input current waveform as switching-mode power supplies. Unfortunately, TC77A, the author of EN 61000-3-2 (formerly IEC 555) has effectively outlawed the conventional (linear) power supply through the harmonic current limits published in EN 61000-3-2. The authors wrote the harmonic requirements rather deliberately to outlaw linear power supplies. They did so without notifying the folks who design products using linear power supplies! I'm frankly surprised the users of linears have not spoken their objections to TC 77A. For linear power supplies in the 75-200 watt range, sometimes a series choke can enable the supply to squeek by the limits. But not always, and never for higher power linears. I'm afraid Jerry is facing a very expensive power supply replacement. Richard Nute +=+ |Richard Nute|Quality Department | |Hewlett-Packard Company |Product Regulations Group | |Barcelona Division (BCD)|Phone : +34 3 582 2820 | |Postal: Avinguda Graells, 501 |FAX : +34 3 582 2515 | |08190 Sant Cugat del Valles |e-mail: ri...@hpbpq6.bpo.hp.com | |Barcelona, Spain|| +=+
