Dear All, Some comments of mine embedded in the message below.
Kind regards Canio Dichirico ---------------------------- > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of John > Cotman > Sent: 21 March 2012 10.50 > To: [email protected] > Subject: RE: [PSES] Mains voltage in Europe > > There is a lot of misinformation (generally, I mean, not on this forum) > about this topic. > > 1. The common 230V is a legal fiction to allow free movement of goods > within the CE marking area. It's a political voltage, not an engineering > one. C.1) Fully sure? IMHO it is a commercial voltage. > > 2. UK mains is therefore nominally 230V, but it happens to be on the high > side, and is the same 240V it always has been. > C.2) I have no experience. > 3. Mainland Europe mains is also nominally 230V, but it happens to be on > the > low side, and is the same 220V it always has been. > C.3) I do disagree. I have been living in Germany for 22 years and the voltage I may measure at any wall socket-outlets both in my flat and within my employer Headquarter is normally around 228-230 V a.c. The contract with my home electricity supply is for 16 A at 400 V a.c. > 4. There is no big handle that anybody can turn to crank the voltage up > or > down. The power stations and intermediate transformers etc were not > designed with such adjustment in mind. No process of meeting in the > middle > is going to happen any time soon. > C.4) I agree. "No big handle" exists "that anybody can turn to crank the voltage up or down" but ±2x2,5% taps are usually available on the high voltage windings of distribution transformers. AFAIK the standard IEC 38 was issued in the late 80's and normalized the nominal voltage 230/400 V for three-phase four-wire or three-wire systems with nominal frequency 50 Hz. A note on that page of IEC 38 read: "The nominal voltage of existing 220/380 V and 240/415 V systems shall evolve toward the recommended value of 230/400 V. The transition period should be as short as possible and should not exceed the year 2003. During this period, as a first step, the electricity supply authorities of countries having 220/380 V systems should bring the voltage within the range 230/400 V +6%, -10% and those of countries having 240/415 V systems should bring the voltage within the range 230/400 V +10%, -6%. At the end of this transition period, the tolerance of 230/400 V ±10% should have been achieved; after this the reduction of this range will be considered." Correspondingly, in CENELEC HD 472 S1, it was stated that "the nominal voltages for low-voltage distribution systems shall evolve towards 400 V". In those days the rated (no-load) secondary voltage of distribution transformers were as follows: 433 V for the 240/415 V systems; 400 V for the 220/380 V systems. (AFAIK the reason is that a distribution transformer *when 100% loaded* must be able to supply the nominal voltage at its LV winding, namely, in those days 415 V and, respectively 380 V.) Obviously the existing distribution transformers could not be changed overnight all over Europe but IEC and CENELEC were aware that this was not necessary. For the UK transformers the primary winding tap +2x2,5% could be used to *reduce* the rated (no-load) secondary voltage from 433 V to about 411 V (at the price of a fully tolerable under-excitement). Correspondingly, in continental Europe, the primary winding tap -1x2,5% could be used to *increase* the rated (no-load) secondary voltage from 400 V to 410 V (at the price of a fully tolerable over-excitement). At the same time, in November 1992, CENELEC, while looking at the future, issued the HD 538.1 S1, dealing with three-phase dry-type distribution transformers: in HD 538.1 S1 the rated (no-load) secondary voltages 410 V and 420 V were established. A note in that HD reads: "Note 2: Rated voltage 410 V is suitable for new transformers in the intermediary steps of bringing low-voltage systems, originally at 380 V, within the range 400 V +6%, -10%." > 5. That said, there is some benefit to continental voltage going up to a > "real" 230V, because for a given power consumption, it would mean less > current, reducing losses and/or increasing grid capacity, and it is > therefore at least under consideration. The contrary effect would arise > if > done in the UK and, since it is not required for any CE marking reason, > would have no obvious merit. > C.5) I do not know the UK market of distribution transformers. For sure the GEAFOL-4GB series cast-resin transformers manufactured by Siemens, with rated power from 100 to 2500 kVA, have rated (no-load) secondary voltage equal to 420 V. This matches with my direct experience about the voltage at my socket-outlets. > 6. CE marked equipment has to be safe across the voltage range it may see > in Europe. Its performance, particularly for heating and lighting > appliances, may of course vary between UK and mainland Europe, but that's > the price you have to pay for a common market. > C.6) Honestly I ignore whether IEC and/or CENELEC are actually pursuing what stated in the above-mentioned note of IEC 38, i.e., "after this the reduction of this range [230/400 V ±10%] will be considered". Does anybody know in this forum? *** End of comments *** > > John C > > > -----Original Message----- > From: John Woodgate [mailto:[email protected]] > Sent: 20 March 2012 17:37 > To: [email protected] > Subject: Re: [PSES] Mains voltage in Europe > > In message <020D0D79F6644B7F84CFED34C7D38DBF@Pete97219Compaq>, dated > Tue, 20 Mar 2012, Pete Perkins <[email protected]> writes: > > > As an outsider my recollection is that the decision to move from > >220V in Continental Europe and 240V in the UK was enthusiastically > >voted in. > > Not by Britain; we resisted for several years before a certain > government official capitulated. > > > > > > The implementatin was scheduled to be a one volt change per year > >with both partine coming together after 10 years with a harmonized 220V > >everywhere. > > That simply isn't practicable and I don't see any reason to do it. > > > > The Continental Europeean change seemed to proceed smoothly. I > >don't know of any issues. The UK change seemed in trouble from the > >beginning; uncertainty reigned. After a couple of years the UK gave up > >trying and abandoned the agreement to change the voltage. > > > > So now the Euro voltage is 230V everywhere except in the UK > >which is > >still 240V. > > Well, it's within 230 V +10 % most of the time in most places, but only > a relatively few supplies were actually reduced: these were supplies to > long rural feeders, where the voltage near the substation was high. > > > > I don't think there is any chance of the tolerance going back to +/-6%. > It would be expensive and probably not bring any significant advantages. > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK > If 'QWERTY' is an English keyboard, what language is 'WYSIWYG' for? > > - > ---------------------------------------------------------------- > 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 > <[email protected]> > > 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 <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> > > - > ---------------------------------------------------------------- > 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- > [email protected]> > > 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 <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> - ---------------------------------------------------------------- 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
