Neven, The standard assumes you're using the 1.2/50us - 8/20us generator specified for testing the AC Power Port in section 4.7... This generator has the built in 2 ohm source impedance. Another clue is Note 10 to Table 4-2 and Note 6 to Table 4-4 which state that you could use a combination wave generator per IEEE C62.41 instead of the 2/10us surge. IEEE C62.41 has an internal 2 ohm source resistor. It seems clear to me that the intent is to add an appropriate series non-inductive resistor of the specified value when using the combination wave generator in place of the 2/10us generator... And yes, the voltage rise time with the combination wave generator will be faster. In addition, the duration of the current wave will be considerably longer, which may deposit higher energy than the 2/10us generator would.... Best Regards,
Michael Hopkins Manager, Customer Technical Center Compliance Test Solutions Thermo Electron Corporation One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Mobile: +1 603 765 3736 [email protected] One Thermo, committed to integrity, intensity, innovation & involvement _____ From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, January 11, 2006 5:46 PM To: [email protected] Subject: 1.2/50 output R for GR1089 Intrabuilding Lightning Surge I am little confused by the requirements of GR1089, if I choose to use 1.2/50 surge generator instead of 2/10 generator. For the 800V 1.2/50 pulse, the standard specifie that a 6 ohm resistor should be added to the generator output. However, there is a 2 ohm built-in resistor in the generator that I have (KeyTek), and I am not sure whether I must have the total output impedance of 6 ohm or 8 ohm. Following the current-limiting logic described in connection with using a 2/10 surge-generator, I tend to believe I can limit the current to 100 A, which would mean that for 800V surge I need 6 ohm in addition to the built-in 2 ohm. But the standard only mentions 6 ohm, so maybe that's the total output R I can have. If I use 6 ohm, I not only test more severely by the nature of the surge waveform (1.2/50 has faster rising edge and longer duration than 2/10), but also by allowing more current through my DUT. Is there anyone on the list who knows the answer? Thanks, Neven - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
