New guy

Rimfire, I replied earlier but did not notice that you had just joined H-M. Welcome aboard. There are many very smart guys and gals hanging out here and all are more than willing to share their knowledge and offer help.
We like pics here too, LOL
 
thank you all for your input,, i'm going to change out the motor to the 3 ph and a vfd thanks again for the help
 
This will be a "theoretical" or hypothetical thought. It just struck me, not very hard, but I have zero experience in the matter. Just the theoretical knowledge of a retired engineer........ Now, it seems that every one is all wound up with converting to 3 phase motors and using the electronicly synthesized variable frequency from the VFDs.

It would seem to me that while single phase motors aren't quite as stable rotationally as a three phase, they do get their speed regulation from frequency, same as a 3 phase motor. By that thought, what would be the problem of acquiring a 3 phase VFD and running a single phase motor from it until such time as the motor conversion could take place?

There would be some limitations, I'm sure. A three phase motor would have a usable output somewhat slower than a single phase. And I assume it would be necessary to disable the phase loss for one leg. But what I see in my mind, a single phase motor should be able to run on a three phase device. Making the voltage match-up, of course. A good many of my machines will work on 120 or 240 volt. Depending on hook-up, of course. 3 phase motors will run on 240 or 480. So, 240 is the common link. For short runs, wire size shouldn't be that expensive.

I guess Sysop should move this thought to a seperate thread in the electrical questions section. It was just a thought that came up as I was thinking about this author's question.
Bill Hudson​
 
Bi11Hudson said:
This will be a "theoretical" or hypothetical thought. It just struck me, not very hard, but I have zero experience in the matter. Just the theoretical knowledge of a retired engineer........ Now, it seems that every one is all wound up with converting to 3 phase motors and using the electronicly synthesized variable frequency from the VFDs.

It would seem to me that while single phase motors aren't quite as stable rotationally as a three phase, they do get their speed regulation from frequency, same as a 3 phase motor. By that thought, what would be the problem of acquiring a 3 phase VFD and running a single phase motor from it until such time as the motor conversion could take place?

There would be some limitations, I'm sure. A three phase motor would have a usable output somewhat slower than a single phase. And I assume it would be necessary to disable the phase loss for one leg. But what I see in my mind, a single phase motor should be able to run on a three phase device. Making the voltage match-up, of course. A good many of my machines will work on 120 or 240 volt. Depending on hook-up, of course. 3 phase motors will run on 240 or 480. So, 240 is the common link. For short runs, wire size shouldn't be that expensive.

I guess Sysop should move this thought to a seperate thread in the electrical questions section. It was just a thought that came up as I was thinking about this author's question.
Bill Hudson​
Click to expand...
Thank you bill. I have a teco vfd coming and will try it on a single phase motor I have.will update as soon as possible
Mike diedrich
 
Matthew/Twindad: having variable speed is wonderful, once you have it you won't want to go back
Mark
 
Mike/Rimfire: You can't use a VFD on a conventional single phase induction motor. You need a 3 phase motor to go with it. Whip out that credit card and start shoppin' ! :D
Mark
 
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