As relates to the EMC Directive, I am trying to straighten out my thoughts re the different classes of standards. I'll say what I thought was right and then ask my questions and ask for comments:
What I thought until now: 1. Basic - underlying standards that have no force themselves but are there to provide test methods and limits or performance criteria for other standards to call out, so that a large number of other standards don't have to repeat and maintain this common material. 2. Generic - standards used in the absence of 3 or 4, that define the required tests and set limits, and may make use of Basic standards for methodology. 3. Product Family - standards that have a scope that covers a family of related equipment, and are mandatory and sufficient only in the absence of 4 below; they define the required tests and set limits, and may make use of Basic standards for methodology. 4. Product Specific - standards that cover a narrowly defined, specific type of equipment, and are therefore mandatory if your product falls within the scope; they define the required tests and set limits, and may make use of Basic standards for methodology. Hierarchy: I thought the situation was that a) you use a Specific standard if there is one, then if not you go for a Family standard, and finally, failing that, you go for the Generic standards b) if you have a Specific a standard applicable to your equipment, the Family and Generic standards have no force, and the Specific standard gives you full presumption of conformity even if it leaves out or contradicts requirements in the broader standards c) if you have a Family standard applicable to your equipment, the Generic standards have no force and the Family standard gives you presumption without using the Generics. Any comments on the accuracy of items 1-4 and a)-c)? My specific question relates, of course, to harmonic currents (collective groan). The product specific standard in question is EN50091-2:1996, which covers EMC requirements for UPS. The scope section states that the standard "will take precedence over all aspects of the Generic Standards and no additional testing is necessary". The omission of a statement that the standard takes precedence over a Product Family standard started me thinking that my assumption b) above is wrong in saying that Product Family standards have no force. If this is a Product Specific standard, and assumption b) above is correct, I am under no obligation to look at EN61000-3-2 which is a Product Family standard. I suspect my assumptions are wrong, and EN50091-2 takes precedence over the Generics but not any Product Family standards that may apply and therefore I need to meet EN61000-3-2. My confusion is escalated by the outdated info in EN50091-2, which has a section on harmonics wherein it says "If the application is within the scope of EN60555-2, the limits and test methodology shall apply" followed by "Note: This subclause is under consideration pending revision of EN60555-2:1987". The combined effect of those two quotes seems to be to allow me to ignore EN60555-2:1987 (which is obsolete anyway). The comments of the group are greatly appreciated, as always. Thanks, Jim Eichner Sr. Regulatory Compliance Engineer Mobile Markets Xantrex Technology Inc. Email: [email protected] Website: www.xantrex.com Any opinions expressed are those of my invisible friend, who really exists. Honest. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
