jpevner
Stainless
- Joined
- Apr 5, 2005
- Location
- Central MA
I wish to run a lathe with a three speed 7.5hp 380v 50hz motor from my 240 single phase house supply. Currently I have a 10 hp RPC which has been working well for years for my other three phase stuff. I also have a decent sized 208-380 transformer from when I had a Deckel mill. Originally, I tried using this, but the lathe didn't want to start on the higher motor speeds. Since then, I put in a 208 volt motor controlled by a VFD. That worked for a while, but recently I started getting motor faults appearing on the vfd. So... I would like to go back to the original motor.
I have been searching threads about this, and it seems that it is unwise to try to run 50hz motors on 380v because of the v/hz ratio?? Ok, so maybe I can use a stepup transformer or stepdown wired backwards. In another thread, it seems that the transformer must be rated specifically for this usage by the manufacturer. Again, ok, I can check for that. There is another thread about wye vs delta that is concerning me. Most of the transformers I see seem to convert wye to delta??
Can I use such a transformer, and how should I connect/ground it? Or do I need a special transformer?
regards,
Jon P.
p.s. Please consider in your answers, that I have a science background, but am not a EE or Elec Power engineer.
I have been searching threads about this, and it seems that it is unwise to try to run 50hz motors on 380v because of the v/hz ratio?? Ok, so maybe I can use a stepup transformer or stepdown wired backwards. In another thread, it seems that the transformer must be rated specifically for this usage by the manufacturer. Again, ok, I can check for that. There is another thread about wye vs delta that is concerning me. Most of the transformers I see seem to convert wye to delta??
Can I use such a transformer, and how should I connect/ground it? Or do I need a special transformer?
regards,
Jon P.
p.s. Please consider in your answers, that I have a science background, but am not a EE or Elec Power engineer.