Roatary Phase converter ??

[muddstopper]

I dont see me ever needing 18hp for anything. The most I would run at the same time might be my lathe, which is already single phase, but I am looking for a newer one, and then possibly a mill. Chances are neither machine would run at the same time and a 10hp converter would be more than adequate. The 25hp 3phase motor is a freebie, so guiney pig it will be. I will experiment with it on a 50amp breaker. But I guess I need some clarification on power draw because i am under the impression that no matter how big the motor, it will only use what power it needs to run the 3phase equipment. To small of a converter and you can burn something up, to big a converter??? Can you really get to big? I know it will take some power to make the converter run, but I would think that unless under a good size load, power consumption would be minimal and not much more than what the equipment would draw if it was just hooked to standard 3phase power. I havent had my wrong quota for today so somebody correct me.

 

[CNC Dan]

What I was trying to explain was that getting a 25hp converter would probably enable him to power 18 hp of equipment, which when operating will take a lot of amps. If he tries to run 18 hp of loaded equipment off a 40 amp breaker I think it would be a no go.

Thats right. The breaker will trip due to current level, not power level.

 

[newbury]

I dont see me ever needing 18hp for anything. The most I would run at the same time might be my lathe, which is already single phase, but I am looking for a newer one, and then possibly a mill. Chances are neither machine would run at the same time and a 10hp converter would be more than adequate. The 25hp 3phase motor is a freebie, so guiney pig it will be. I will experiment with it on a 50amp breaker. But I guess I need some clarification on power draw because i am under the impression that no matter how big the motor, it will only use what power it needs to run the 3phase equipment. To small of a converter and you can burn something up, to big a converter??? Can you really get to big? I know it will take some power to make the converter run, but I would think that unless under a good size load, power consumption would be minimal and not much more than what the equipment would draw if it was just hooked to standard 3phase power. I havent had my wrong quota for today so somebody correct me.

I'm pretty sure you are correct in that it won't draw a lot more power than your mill.

 

[Big Barn]

I havent had my wrong quota for today so somebody correct me.

Send me your address, Bill. I think quota is transferable. I can top it up for you.

Terry

 

[CNC Dan]

I'm pretty sure you are correct in that it won't draw a lot more power than your mill.

that's right. won't use much power, but might need a lot of current.

How can it need a lot of current if it uses little power? Power Factor.

The current in an unloaded motor is not in phase with voltage. So at some point in the AC cycle you are drawing power fron the grid, and some point you sending power back into the grid. The result is that you use little power overall, but there is a lot of current flowing. So you may need heavy wire, and large breakers.

 

[Kyle_in_Tex]

Send me your address, Bill. I think quota is transferable. I can top it up for you.

Terry

good one.

 

[ultrarunner]

Interesting story. Please do not question me on the technical aspects of it as I am totally ignorant but...

Years ago an elderly retired machinist/inventor/genius friend had a converter in his basement workshop to run his 3 phase welder. He said when welding the meter would actually run backwards. His comment at the time was the more he welded the more money he saved.

Sadly he passed away many years ago. I wish I had the time back then to pay more attention. Terry

Had the same with my retired machinist friend and he showed me... thing is we all have smart meters now and apparently the smart meters don't run backwards?

 

[Big Barn]

Had the same with my retired machinist friend and he showed me... thing is we all have smart meters now and apparently the smart meters don't run backwards?

I was once told that was deliberate to punish the "alternate source" power users so that they could not receive 'credit' when back feeding into the grid.

Terry

 

[ultrarunner]

I was once told that was deliberate to punish the "alternate source" power users so that they could not receive 'credit' when back feeding into the grid.

Terry

Same has been said here... the analog meters were very simple... all they did was measure the flow of current... adding one way and subtracting the other.

 

[BukitCase]

"I was once told that was deliberate to punish the "alternate source" power users"

Yup, apparently the power companies finally learned a business lesson from the insurance companies ...Steve