Does CE + CE = CE? My simple interpretation of this is that the boundary for modularity ends at the enclosure that the customer sees.
A short and sweet example based upon one of our designs is: We make a unit incorporating a CE marked open frame power supply. We use a CE marked processor card. Our unit interfaces to a printer. For our unit, we cannot use CE + CE = CE as it applies to the open frame power supply and processor card. We have design control over the enclosure that our customer sees around these components. As such, we have to build a prototype of our enclosure and have our unit tested for EMC and safety. Once the unit passes, we write our Declaration of Conformity and put the CE mark on the enclosure of our unit. However, we can use CE + CE = CE as it applies to the printer. Why? Because we have no design control over the printer's enclosure. During EMC and safety testing, we use any CE marked printer as a dummy load for our printer port. We exercise this port during the testing to ensure that our end of the interface holds up. If we pass testing with the CE marked printer, then we can assume that any other CE marked printer can be used. This is the reasoning that I use as my starting point to determine modularity. Only experience can help with the other factors such as interface requirements ... > -----Original Message----- > From: Alan E Hutley [SMTP:[email protected]] > Sent: Monday, March 27, 2000 9:25 AM > To: [email protected] > Cc: emc-pstc discussion group > Subject: Re: Is the "modular approach to EMC" the same as CE + CE = > CE? > > Canio > > In the EMC+LVD +Machinery Yearbook 1999 was an excellent article on this > very subject by Neil Harvey who at that time was with BSI. > The summary said " It is never possible to be sure that a system will be > compliant, when using the CE+CE=CE approach. As a result, the decision > regarding its adoption and use is fundamentally a matter of sound > judgement, flavoured with careful risk assessment" > Regards > Alan E Hutley > Editor > EMC+Compliance Journal > [email protected] <mailto:[email protected]> > www.emc-journal.co.uk <http://www.emc-journal.co.uk> > > > ----- Original Message ----- > From: Canio Dichirico <mailto:[email protected]> > To: IEEE EMC List <mailto:[email protected]> > Sent: Monday, March 27, 2000 01:30 > Subject: Is the "modular approach to EMC" the same as CE + CE = CE? > > Hi All! > > The designer/manufacturer of a (prototype) system has recently > exposed to me the following argument. If the system is built out of > subsystems that are CE-marked, the complete system may be considered > compliant with the EMC Directive 89/336/EEC. The designer stated that this > is possible on the basis of the "modular approach to EMC". > > In order to understand this argument I read the paper "Update on the > European Union's EMC Directive", appeared on the European Edition of > Compliance Engineering - 1999 Annual Reference Guide. In this paper one > may read that "For systems and installations ... either a system or a > modular approach may be used to demonstrate compliance. The TCF [Technical > Construction File] route is thus not required for verifying a system > and/or installation if all subunits and subsystems comply with the EMC > requirements (modular approach), presuming that the referenced standards > are relevant for intended environments and that installation guidelines > are followed." > > Does what I read on Compliance Engineering confirm what declared by > the (prototype) system designer? > > Which are the "installation guidelines" that the paper quoted above > is referring to? Which are the differences, if any, between the "modular > approach" and the "equation" CE + CE = CE? I remember reading in this > forum (plenty of times) that CE + CE does not necessarily equal CE. > > Any replies or comments are welcome. > > Thank you all in advance! > > > In the EMC+LVD +Machinery Yearbook 1999 was an excellent article on > this very subject by Neil Harvey who at that time was with BSI. > The summary said " It is never possible to be sure that a system > will be compliant, when using the CE+CE=CE approach. As a result, the > decision regarding its adoption and use is fundamentally a matter of sound > judgement, flavoured with careful risk assessment" > Regards > Alan E Hutley > Editor > EMC+Compliance Journal > [email protected] <mailto:[email protected]> > www.emc-journal.co.uk <http://www.emc-journal.co.uk> > > Canio Dichirico > European Southern Observatory > Technical Division - Electronic Systems Department > Karl-Schwarzschild-Str. 2 > D-85748 Garching bei München > > Tel. +49-89-3200 6500 > Fax +49-89-320 23 62 > email: [email protected] <mailto:[email protected]> > website: www.eso.org <http://www.eso.org> > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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