I've been searching for "isolation transformer" but they all seem to be 480 to 240 or similar. Not had any luck so far on finding a 240-240 transformer.
John On 5/28/2012 5:00 AM, gene heskett wrote: > On Monday, May 28, 2012 05:46:09 AM andy pugh did opine: > >> On 28 May 2012 09:39, gene heskett<ghesk...@wdtv.com> wrote: >>> True, they just wind 3 sets of coils on a 3 legged core. My suggested >>> use was to convert the delta connected source with its 'wild leg' >>> into a wye connected source that doesn't have the wild leg because >>> the center of the wye is now connected to the neutral bus. >> The manual that I linked to earlier in the threrad (page 7/205 >> onwards) doesn't show any neutral connection to the infeed module. >> however it does show a number of differing earth wiring options, some >> of which include an autotransformer with earthed neutral point. >> >> What is interesting is that the infeed filters are earth-referenced, >> and perhaps this is the problem. What earthing scheme would a rotary >> converter actually match? >> > Exactly why I suggested the 3 phase 1/1 isolation transformer, to convert a > circuit which is not well earth referenced, into one that is. > >> An interesting section is.. >> "TN-C-S, TN-C-C: Symmetrical 4–conductor or 5–conductor three–phase >> line supply with >> grounded neutral point with a protective and neutral conductor >> connector connected >> at the neutral point which, depending on the line supply type, uses one >> or several conductors. >> "For other line supply types 1) the NE module must be connected through >> an isolating transformer." >> > Right there it is. I would think the isolation transformer would fix it. > This commonly used method of making 3 phase power does NOT have a grounded > neutral point. > >> Which seems to very much tie in with what Gene is saying, unless, of >> course, the Rotary converter itself counts as an autotransformer. > It is essentially an auto transformer, it is NOT an isolation transformer. > Autoformers as we call them do not isolate by definition. It's all one > winding (per phase) to step up or down. > >> I think that the converter provides an "IT" supply and that is shown >> with an autotransformer in the diagrams. > That could be for different reasons. This isolation transformer, wired as > I suggested, should restore the grounded neutral this kit needs. > > Cheers, Gene ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
