I read in !emc-pstc that Brian Epstein <[email protected]> wrote (in <[email protected]>) about 'harmonics testing' on Thu, 22 May 2003:
>We make a product that has several components that plug into the power mains >including a computer, two monitors, and two units that we manufacture >ourselves. When all these components are tested for power current harmonic >emissions together, they fail. When tested separately, they pass. Is it >reasonable to assume that if we ship the system to Europe with a power strip >that we have to test all components together, but if we do not include a >power strip, we can test each component for harmonics separately? It doesn't work quite like that. You need to look at the special definitions of 'system' and 'installation' in the Directive and the Guidelines. You may be surprised at the following, but I believe it is true and no- one has specifically said that it is not: If the whole kit is catalogued, priced and invoiced at a single inclusive price, then it is a 'system', as defined in the Directive and the Guidelines, and must be tested as a single entity. If you have to go down this route, consider that you can buy off-the- shelf power supplies with active PFC now for only a few dollars more, and these meet the limits with a wide margin. You may find that just changing the power supplies in the units that you make is sufficient. If the items are catalogued, priced and invoiced as separate items, and purchasers can choose which items to buy, then there is no one kit that the manufacturer can test; instead each item is tested separately. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
