Chris Radek wrote: > On Tue, Oct 21, 2008 at 01:11:04PM -0700, Kirk Wallace wrote: >> Chris, I am just being curious, your BP currently has a 3-phase main >> transformer that supplies the servo drives and maybe other things? The >> 3-phase Xfmr expects 415 VAC on each leg which ends up as 100 VDC for >> the servo drivers? What voltage and phase do you want to input? The BP >> isn't that big of a machine, I am having a hard time understanding why >> you need a 100 pound transformer. > > I bet my rambling was just unclear! > > Currently it has a 3 phase 240->72 volt transformer. When I convert > it to EMC I want to be able to run it on my single phase power. > > So I have a 415->120 single phase transformer that I will use instead > of the current one. I will run 240 into the 415 winding and get about > 70 out. I will also probably have to upgrade the diodes and > especially add some more capacitance. > > The transformer is so heavy because it's single phase; a single phase > transformer has much more iron than a three phase of the same power > rating. >
The transformer is also heavy because of the reduced voltage. Since you'll be feeding 240V into a 415V winding, the usable VA is only 240/415 = 58% of the actual VA. However, IIRC the transformer was surplus and the cost per VA was low enough that even 58% utilization is a win (assuming you can mount it). Regards, John Kasunich ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
