On 27/7/13 12:00 AM, "John Woodgate" <j...@jmwa.demon.co.uk> wrote:
> In message <ce18b7b1.1bc02%scott...@gmail.com>, dated Fri, 26 Jul 2013, > Scott Xe <scott...@gmail.com> writes: > >> Appreciate your good advice! My further check with the multiple >> sockets indicates that although the power cable consists of 3 cores, >> the earth connection is for the mains sockets connection and the >> product is of class >> 2. I compared with other similar type of portable extension sockets >> and believe they are all of class 2 and the earth connection has no >> relation to its safety construction. Thus the data shall be: >> >> 240 V AC 50 Hz "Double Square Symbol" > > I do not believe this is correct. It is difficult when it is not clear > which safety standard applies, but if a product has a safety earth > conductor in the cable, it *must* be regarded as Class I. Class I > products are allowed to have parts that meet the requirements for Class > II. Scott: If the cable consists of earth core, the product is regarded as Class I product. In this case, it may not be correct since the earth connection must be connected for those 13A multiple sockets on the conditions that EN 60950-1 is for USB sockets part and BS 1363-2 for multiple sockets part. > I looked at several extension sockets here, and none have the > double-square symbol, but they also do not have the statement "This > product must be earthed". They do have statements about connecting the > product with the correct 13 A cable to a 13 A plug. Scott: Your observation is correct. The products neither have the statement "This product must be earthed" nor double square symbol. What is the safety construction for this product? Not class I and II, what else? Your second statement is probably for the portable extension socket without a cable and but with a AC inlet connector instead. In BS 1363-2, it does not mention class I and II while EN 60950-1 does. If we look at the multiple sockets only, it neither require "This product must be earthed" nor "Double Square Symbol" in BS 1363-2. If the product comes with a power cord (most of current product do), there should be no "This product must be earthed" and "Double Square Symbol". It leaves to the USB socket part that complies with EN 60950-1 that requires double square symbol for class II products. Is the double square symbol required due to USB sockets part? - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ 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 <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
