Start from the lowest limit in Table 1 and work up. >From your example #1: 30/60 <= 1; 35/(1.17*60) <= 1; both conditions true, therefore Um < 60. >From your example #2: 200/120 <= 1; NOT true, therefore go to next limit in Table 1; 200/2000 <= 1; 205/(1.17*2000) <= 1; both conditions true, therefore Um < 2000 Regards,
Jeff Jenkins Senior Regulatory Compliance Engineer Advanced Energy Industries, Inc. Fort Collins, CO USA 80525 Opinions are my own and not necessarily shared by Advanced Energy Industries, Inc. or its affiliates. -----Original Message----- From: Arjen Dragt [mailto:[email protected]] Sent: Monday, April 19, 1999 3:01 PM To: EMC-PSTC Listserv Subject: EN 50178 clause 5.2.13 In case (b) of this clause, I do not understand how the decisive voltage (classification) is to be correctly calculated. For those of you who have the standard, try using (for example) Udc = 30 V and Udcp = 35. The method outlined in the standard (with the formula given) will indicate that in this case, Um is 2000 Vdc. For a voltage Udc = 200 V, Udcp = 205, the method will indicate that the circuit lies in the Um = 120 V category. Either I am missing part of the "picture", or there is something wrong with the way that the formula is laid out. Hopefully somebody can make this clear for me. Arjen --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
