On Thu, 10 Jan 2008 10:50:38 -0700, "Aldous, Scott" <[email protected]> wrote:
> I've come across specs referencing grounding classes from Japanese > customers, i.e A class grounding, D class grounding. > > Googling doesn't turn up much - it appears that this class is related to > the allowable impedance in the ground path (10 Ohms or less for class A > or C, 100 Ohms or less for class D). The requirement is slightly complicated, but in briefly, Class A and B are for high voltage and extra-high voltage facilities, Class C is for low voltage facilities exceeding 300V, and Class D is for low voltage facilities not exceeding 300V. In general, maximum impedance, at the mains frequency, from the grounding point to the soil is 10 ohms for Class A and C, and 100 ohms for Class D. However, most equipment manufacturers don't have to worry about the requirement, as the requirement would be applied not to the equipment themselves but rather to their installation works. Regards, Tom Tomonori Sato <[email protected]> URL: http://homepage3.nifty.com/tsato/ - 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
