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

[nhengineer]

Rotary Phase Converter Plans for Sale - $12.50



$12.50 - Click here to buy now via PayPal and download instantly

30-day money-back guarantee.
If you purchase these plans and are not 100% satisfied, we'll refund your purchase price.

These plans include:

• A 44-page PDF instruction manual including:
• 15 technical drawings.
• 4 photos.
• 4 tables.

Feel free to post any questions you may have in this discussion, either before you purchase or during construction. Or, post pictures of your finished rotary phase converter.

Questions about buying tool plans? See: http://www.homemadetools.net/forum/f...6068#post65876

$12.50 - Click here to buy now via PayPal and download instantly

[Leprechaun]

It would be very helpful to add information about the cost of materials to the description, and inclusion of a BOM would be great.

[Jon]

Good point Leprechaun; adding a BOM in the description has been mentioned before, I think we might make that the standard. Estimated cost is wise too; people can save a lot of money by building tools like this. We can add up the materials cost beforehand, and then compare them to the cost of purchasing a ready-built tool. People will be able to see an exact dollar amount that they can save by building this tool. For this Rotary Phase Converter, the savings from building from plans as opposed to buying are probably in the hundreds of dollars.

We've only had these plans for sale for a week, but many people have shown interest. Last week Paul Alciatore broke our first week sales record with his highly-detailed Quick Change Tool Post plans. Now nhengineer has gone and done the same thing with these Rotary Phase Converter plans.

It looks like a lot of people are going to be saving money on a rotary phase converter build, because in just one week, 20 copies of these plans have been sold.

[nhengineer]

I thought of including prices when I was creating the booklet but decided not to. Prices change with time and economic situations. In order to keep my booklet accurate, I would need to update it monthly. In addition, all of my designs are junkyard and salvage yard friendly.

If one were to purchase a 7½ HP 3-phace motor new, it would cost more than $1,000. I got the one shown in the booklet for $10. It would be misleading to publish either price as the gold standard.

I got the pony motor for free when my FHA furnace crapped out and I had to get a replacement. The pony motor started its life as a hot air blower motor.

All the steel used in the design was surplus from other projects. My cost for the converter was in the neighborhood of $50 including fasteners and shop electricity & heat.

.... I'm just saying ....

The BOM is on page 9 by the way.

[Marc Broussard]

Hi. Three phase motors are very cheap. The junk yards sell them for scrap price here. I have a 7 1/2 HP they sold me for 14$. And most single phase motors 1/2 hp or bigger will spin a big 3-ph one. I have all the components to build one right now but, if I use my 3-ph motor for a converter I won't have anything 3-ph to run. Go figger.

[smithdoor]

Sound like it will work
Do you photos or drawing you post
If you using a three-phase motor as you converter it is working as a generator making as some call the third leg

Dave

Hi. Three phase motors are very cheap. The junk yards sell them for scrap price here. I have a 7 1/2 HP they sold me for 14$. And most single phase motors 1/2 hp or bigger will spin a big 3-ph one. I have all the components to build one right now but, if I use my 3-ph motor for a converter I won't have anything 3-ph to run. Go figger.

[old kodger]

Hi folks,
I'm in Australia and I downloaded David's converter plans, unaware that in the States you have what is called high single phase.
Now my comprehension of that, from an Aussie point of view, is that you actually have two 120 volt phases and neutral return giving you 220 volts across the two phases.
In Australia we have 220volt single phase BUT it's only one hot line and one neutral return and the neutral is bonded to earth.

I've been in discussion with David over this and he was not aware of this situation, when this was made clear, he agreed that his design would not work in areas with this configuration of grid supply, and suggested that I post this information on the forum as a "heads up" to others contemplating building this design.

It's a bit of a sod that this exists because I've got several three phase bits of equipment and only a single phase supply (we recently moved house).

Best of Luck to all,

Rob.

[Mcgyver28117]

Hi folks,
I'm in Australia and I downloaded David's converter plans, unaware that in the States you have what is called high single phase.
Now my comprehension of that, from an Aussie point of view, is that you actually have two 120 volt phases and neutral return giving you 220 volts across the two phases.
In Australia we have 220volt single phase BUT it's only one hot line and one neutral return and the neutral is bonded to earth.

I've been in discussion with David over this and he was not aware of this situation, when this was made clear, he agreed that his design would not work in areas with this configuration of grid supply, and suggested that I post this information on the forum as a "heads up" to others contemplating building this design.

It's a bit of a sod that this exists because I've got several three phase bits of equipment and only a single phase supply (we recently moved house).

Best of Luck to all,

Rob.

Clarification

Actually here in the States we do not refer to this as two phases, its just single phase... Its 208-240 VAC depending on the transformer providing the service to the customer... Both Residential and Industrial the single phase is provided with a center tap off the transformer, this leads to 120 vac legs, that are hot with respect to neutral. Neutral is also earth ground at both the transformer pole and at the circuit breaker load center... But the hot legs are always opposite polarity to each other so they have a maximum voltage of 208-240 vac when connected across the two hot legs of the transformer secondary output... The neutral wire or center tap, carry's current based on the loading in each hot leg, if one hot leg is carrying more current than the other, this will cause a flow of current in the neutral or center tap wire.

Sincerely,
Ron

[nhengineer]

Clarification

Actually here in the States we do not refer to this as two phases, its just single phase... Its 208-240 VAC depending on the transformer providing the service to the customer... Both Residential and Industrial the single phase is provided with a center tap off the transformer, this leads to 120 vac legs, that are hot with respect to neutral. Neutral is also earth ground at both the transformer pole and at the circuit breaker load center... But the hot legs are always opposite polarity to each other so they have a maximum voltage of 208-240 vac when connected across the two hot legs of the transformer secondary output... The neutral wire or center tap, carry's current based on the loading in each hot leg, if one hot leg is carrying more current than the other, this will cause a flow of current in the neutral or center tap wire.

Sincerely,
Ron

Ron,

Thanks for that clarification. I'm curious though; is our 208/240 actually 2-phase? I've had some folks refer to it as 2-phase but I haven't been able to confirm that it is. It would depend on how the transformer was wound wouldn't it?

[Mcgyver28117]

Well it kinda goes like this, people become familiar with 3 phase and associate it with 3 wires, then they later see 2 wires and say hey it's 2 phase... but that is not how it works, nor what it means... with 3 phase their are 3 sine waves 120 degrees apart, if one has a 3 channel oscilloscope, this can be see as the some wave between legs a to b, leg b to c and legs c to a... with only 2 wires, we have only one sine wave or one phase, the center tap only provides a voltage divide by 2 function, stiil just one sine wave, because if we have an equal numbers of devices on the leg a to center tap and leg b to center tap, we have no current flow through the center tap... It's just one phase...

Ron