In message <0ed66cd2c9bd0a459d54fb9119a60567ca9...@mailserver.lecotc.com>, dated Fri, 5 Dec 2008, "Kunde, Brian" <brian_ku...@lecotc.com> writes:
>We do not want to overburden your customer with private vs public >distribution systems issues, so how common is it for a non-residential >location such as a business, shop, laboratory, factory, office >building, etc. to be powered by a public vs private distribution >system? In the US, most non-residential locations would have their own >transformer but I'm told this is not the case in Europe. Correct. In the context of the standards, a private supply is derived >from the infrastructure through an MV/LV or HV/LV transformer. It doesn't mean a privately-generated supply. I don't know that there is a fixed power level at which a MV/LV or HV/LV transformer is preferred, but it is certainly over 30 kW. > >We have some products that draw 40-50 amps at 230VAC that use high >power heating elements that must use phase control to be able to keep >the temperature in an oven within a very tight specification (high tech >analytical equipment). We have found no other practical way to control >the temperatures and not shorten the life of the expensive heating >elements, so we specify that such devices must be powered by a Private >Distribution System or to seek the permission from your utility company. Well, 10 kW sine-wave dimmers for theatrical lighting are now available, but they are still somewhat (not vastly) more costly than phase-control. However, I expect that where your products are used, the supply is almost certainly private. > >What we struggle with here in R&D is are we causing a hassle for our >European Customers? You could be, if you don't implement the warning instructions that I described. And the 'hassle' might not stop at your customers; your company might be in trouble under certain circumstances. >Our sales force seems to be able to sell them without any complains. I >wonder how closely such things are monitored in Europe. It varies from country to country. Be very careful in the Hamburg area, for example, where harmonic levels are generally very high and may be closely monitored. There are also places in France where the same applies. >I assume as long as you are not blowing up transformers it will not get >much notice. Don't rely on that. While it's generally difficult to track down sources of harmonics, it isn't difficult if the increase in level is seen to occur during routine monitoring. It's then not too difficult to find out what has recently been installed and connected to the network. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Either we are causing global warming, in which case we may be able to stop it, or natural variation is causing it, and we probably can't stop it. You choose! John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. 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...@ptcnh.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
