John, Thanks for the update.
JRC On Sun, Mar 27, 2011 at 6:02 AM, John Thornton <bjt...@gmail.com> wrote: > I can't find my drawings atm, so I'm recreating them from scratch and > will post them as soon as done. Just wanted to let you know I did not > forget although sometimes I do. > > John > > John Crane wrote: > > Thanks, > > > > John R. Crane > > > > On Mon, Mar 21, 2011 at 7:27 AM, John Thornton<bjt...@gmail.com> wrote: > > > > > >> John, > >> > >> I'll dig out my schematic and make sure it is up to date and figure a > >> way to post it to the list. > >> > >> John > >> > >> John Crane wrote: > >> > >>> John, > >>> > >>> I would like to know more about the way you have engineered your phase > >>> converters. I am in the process of adding this capability in my shop. > >>> > >>> Thanks, > >>> > >>> John R. Crane > >>> > >>> On Thu, Mar 17, 2011 at 5:53 AM, John Thornton<bjt...@gmail.com> > wrote: > >>> > >>> > >>> > >>>> I have three rotary phase converters. The are all using a potential > >>>> relay for the start caps and a relay that pulls in the mains. So I > don't > >>>> have to hold the push button and if the power drops out for a few > >>>> seconds the phase converter does not try and restart without the start > >>>> caps. I've not had the fun of blowing anything up when building them. > >>>> They are all balanced phase to phase within a couple of volts. However > >>>> phase to phase the run caps are very different in order to get the > >>>> voltage phase to phase to balance. I can post some details if anyone > is > >>>> interested... > >>>> > >>>> John > >>>> > >>>> Dave wrote: > >>>> > >>>> > >>>>> Back when I put my 10 hp phase converter together, I found some > charts > >>>>> on the web someplace about suggested capacitor sizing. I found a > >>>>> > >> cheap > >> > >>>>> supply of capacitors at Mendelson's in Dayton, Ohio > >>>>> and bought a small box of them. I ended up using I believe, 4 - 330 > >>>>> > >> uf > >> > >>>>> 330 volt units as starting caps and 4- 135 uf run caps. I use a > push > >>>>> button to start the motor and as long as I hold the button > >>>>> down the starting caps are wired into the circuit. When the motor > >>>>> > >> spins > >> > >>>>> up I release the button. I tried to use a voltage sensitive relay, > >>>>> like the ones used on refrigeration systems and AC systems, but > >>>>> it was not reliable probably due to the high current from the large > >>>>> number of caps. There is also a motor contactor that seals itself in > >>>>> via the button push. That way if the line power drops, the > contactor > >>>>> drops out and the converter idler motor and he > >>>>> attached slave motors are powered down. > >>>>> > >>>>> The math relating to how this works gets even more complicated when > you > >>>>> consider the effects of hooking a 3 phase motor that you are going to > >>>>> start (a slave motor) across the the idling phase converter motor. > >>>>> For a brief period of time, the idler motor becomes a generator. > The > >>>>> rotor slows slightly and the energy in the rotor pumps power into the > >>>>> three phases and spins up > >>>>> the slaved motor. It works very well. > >>>>> > >>>>> During experimentation, it is very obvious when more starting > >>>>> > >> capacitors > >> > >>>>> are required as the motor will simply not spin up. > >>>>> Adding more run caps helps balance the phases but they never really > >>>>> fully balance. > >>>>> > >>>>> Safety glasses are very good idea when experimenting. Starting > caps > >>>>> go off like firecrackers if you overstress them. They are only > >>>>> designed to be switched in for a few seconds. > >>>>> > >>>>> A source of cheap starting caps is a really good idea if you want to > do > >>>>> some phase converter experimentation. I blew up several of them. > >>>>> > >>>>> Dave > >>>>> > >>>>> On 3/14/2011 9:01 PM, Jon Elson wrote: > >>>>> > >>>>> > >>>>> > >>>>>> > >>>>>> > >>>>>>> On 14 March 2011 10:50, John Thornton<bjt...@gmail.com> > wrote: > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>>> Is it not amazing that the hillbillies from backwoods Missouri > with > >>>>>>>> > >> a > >> > >>>>>>>> 3rd grade education can make a rotary phase converter without all > >>>>>>>> > >> the > >> > >>>>>>>> math... > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>> > >>>>>>> > >>>>>> Of course! The trick is the windings in the motor do all the math > for > >>>>>> you, all you need to do is hook up the wires. > >>>>>> > >>>>>> Jon > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>> > >> > ------------------------------------------------------------------------------ > >> > >>>> > >>>>>> Colocation vs. Managed Hosting > >>>>>> A question and answer guide to determining the best fit > >>>>>> for your organization - today and in the future. > >>>>>> http://p.sf.net/sfu/internap-sfd2d > >>>>>> _______________________________________________ > >>>>>> Emc-users mailing list > >>>>>> Emc-users@lists.sourceforge.net > >>>>>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>> > >>>>> > >>>> > >> > ------------------------------------------------------------------------------ > >> > >>>> > >>>>> Colocation vs. Managed Hosting > >>>>> A question and answer guide to determining the best fit > >>>>> for your organization - today and in the future. > >>>>> http://p.sf.net/sfu/internap-sfd2d > >>>>> _______________________________________________ > >>>>> Emc-users mailing list > >>>>> Emc-users@lists.sourceforge.net > >>>>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>>>> > >>>>> > >>>>> > >>>> > >>>> > >> > ------------------------------------------------------------------------------ > >> > >>>> Colocation vs. Managed Hosting > >>>> A question and answer guide to determining the best fit > >>>> for your organization - today and in the future. > >>>> http://p.sf.net/sfu/internap-sfd2d > >>>> _______________________________________________ > >>>> Emc-users mailing list > >>>> Emc-users@lists.sourceforge.net > >>>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>>> > >>>> > >>>> > >>> > >> > ------------------------------------------------------------------------------ > >> > >>> Colocation vs. Managed Hosting > >>> A question and answer guide to determining the best fit > >>> for your organization - today and in the future. > >>> http://p.sf.net/sfu/internap-sfd2d > >>> _______________________________________________ > >>> Emc-users mailing list > >>> Emc-users@lists.sourceforge.net > >>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>> > >>> > >> > >> > ------------------------------------------------------------------------------ > >> Colocation vs. Managed Hosting > >> A question and answer guide to determining the best fit > >> for your organization - today and in the future. > >> http://p.sf.net/sfu/internap-sfd2d > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > >> > > > ------------------------------------------------------------------------------ > > Enable your software for Intel(R) Active Management Technology to meet > the > > growing manageability and security demands of your customers. 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