Rotary Phase Converter (Create 3-phase power from a single phase source)

[smithdoor]

That is still single phase in drawing with center tap transform
I see why the confusion But this is single phase power AKA as 3 wire single phase
This type is use all over the USA & CA for homes and offices 3 wire. A long time ago they found this voltage use homes was safer than 220 volts.

Most do know this today is at time the USA had both 50 & 60 Hz about 40 years a hear of this from old time electrician having to convert to 60Hz . The only time may see this is on very old motor lay around in old shop

Dave

Well Frank S, after further review, I believe you may be correct. See drawing below:

Attachment 16140
Image modified & copied from HERE

It appears that my design, slightly modified, will work for Australia and other former British Crown Colonies nations. All one would need is an appropriately sized transformer. I will work on that.

Reader comments welcome.

[Paul Alciatore]

Bravo! That's what I was saying. Thanks for the drawing.

Well Frank S, after further review, I believe you may be correct. See drawing below:

Attachment 16140
Image modified & copied from HERE

It appears that my design, slightly modified, will work for Australia and other former British Crown Colonies nations. All one would need is an appropriately sized transformer. I will work on that.

Reader comments welcome.

[nhengineer]

That is still single phase in drawing with center tap transform
I see why the confusion But this is single phase power AKA as 3 wire single phase

Dave

Please Smithdoor, go look at the drawing again and then follow the link. It is clearly explained, both on the drawing and in the text of the link, that you begin with 2-wire single phase (left side of drawing) and wind up with 3-wire 2 phase 180° apart (middle of drawing).

[smithdoor]

Yes it say split phase so NOW it on the internet it must be true

But when make drawing for the city or county That is a 3 wire single phase
That will not start a 3 phase motor with additional caps for starting and last I heard We are taking about 3 phase

Good luck with internet

Dave

Please Smithdoor, go look at the drawing again and then follow the link. It is clearly explained, both on the drawing and in the text of the link, that you begin with 2-wire single phase (left side of drawing) and wind up with 3-wire 2 phase 180° apart (middle of drawing).

[nhengineer]

But when make drawing for the city or county That is a 3 wire single phase
That will not start a 3 phase motor with additional caps for starting and last I heard We are taking about 3 phase

Dave

Geekers Smithdoor, we're using a pony motor to start the idler turning. I'll post the original schematic to show the original design but I'll have to reboot first.

[smithdoor]

I just look at your drawing on the first page
I like using a simple way capacitor and potential relay
Low cost an time proven Today it use for AC and water well pumps on single phase
I have seen the pony type with no more than a lawn mover pulley and rope for starting it works and simple
The one I saw the guy raped the rope around the pulley mounted on the idler motor, pulled the rope and switch the motor on it work. I could not use with employs. so I used capacitor and potential relay it is automatic

Dave

Geekers Smithdoor, we're using a pony motor to start the idler turning. I'll post the original schematic to show the original design but I'll have to reboot first.

[nhengineer]

But when make drawing for the city or county That is a 3 wire single phase
That will not start a 3 phase motor with additional caps for starting and last I heard We are taking about 3 phase

Dave

The trick is to find the appropriate transformer that is 1:2 with a center tap on the output. That will take some research on my part. (corrected 2017-01-18)



Smithdoor, we are going from 2-wire single (one hot & one earth ground) to 3-wire 2-phase (2 hots & one earth ground) to 4-wire 3-phase (3 hots [kind of] & one earth ground). The required transformer (if it exists) would not be cheap but probably more economical than purchasing a single phase motor to drive the equipment.

[smithdoor]

There is a 3 wire 2 phase this drawing is not 2 phase This is 3 wire single phase
Yes it said on drawing some else but it is only wishful thinking only
At one time there was 4 wire 2 phase power in the USA back about 1900 come from power plants it died

It is on internet it must be true but still will not work.

Dave

The trick is to find the appropriate transformer that is 1:1 with a center tap on the output. That will take some research on my part.



Smithdoor, we are going from 2-wire single (one hot & one earth ground) to 3-wire 2-phase (2 hots & one earth ground) to 4-wire 3-phase (3 hots [kind of] & one earth ground). The required transformer (if it exists) would not be cheap but probably more economical than purchasing a single phase motor to drive the equipment.

[old kodger]

Hi Rhengineer,
The transformer thing will likely work, but would it not have to be 1:2 in order to input 230volts and get two lots of 230 volts (center tapped) 180 degrees out of phase?
Also, each time an idea (opinion) has been postulated on this thread, I've gone and done whatever research I could, and in every case IN AUSTRALIA the cost has not been justifiable.
Now to throw another consideration into the fray, since the acquisition of an idler motor is mandatory in all instances, if one were to forcibly drive an idler motor with say, a diesel motor, (motors from old banged up utes are not so hard to get), would it produce all three phases?

Rob.

[Frank S]

Hi Rhengineer,
The transformer thing will likely work, but would it not have to be 1:2 in order to input 230volts and get two lots of 230 volts (center tapped) 180 degrees out of phase?
Also, each time an idea (opinion) has been postulated on this thread, I've gone and done whatever research I could, and in every case IN AUSTRALIA the cost has not been justifiable.
Now to throw another consideration into the fray, since the acquisition of an idler motor is mandatory in all instances, if one were to forcibly drive an idler motor with say, a diesel motor, (motors from old banged up utes are not so hard to get), would it produce all three phases?

Rob.

What you would be doing there is building a generator then you would need an AVR ( automatic voltage regulator) to hold it at the correct HZ
Also without line voltage to the motor now being used as a generator it would require a source excite the field winding.