On Saturday, June 02, 2012 12:22:59 AM Jon Elson did opine: > gene heskett wrote: > > On Friday, June 01, 2012 06:50:05 PM John Thornton did opine: > >> I posted on the C(ommerical)NCZone and a guy there says those drives > >> are rated for a 3% inductance wye isolation transformer. > >> > >> John > > > > BS alert there John. 3% of what? Without a frame of reference you may > > as well be shopping for a good used car. > > No, this is actually standard power engineering terminology. I don't > recall the > way this is measured, but it has a specific definition to a power EE. > The basic concept is this % inductance tells you what the fault current > and sag will be under particular loads.
Sounds like another way to state equivalent series impedance or as applied to capacitors, equivalent series resistance, or ESR. 3%, from a solid 3 phase source wouldn't be so bad, but from a saggy RPC? 1% would be better, but would take more copper & higher priced iron. > But, of course, this refers to running the transformer from a stiff > 3-phase mains > supply, not a saggy rotary converter. > > Jon Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> Much of the excitement we get out of our work is that we don't really know what we are doing. -- E. Dijkstra ------------------------------------------------------------------------------ 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
