Dynasty 200 Rotary Phase Converter question

[tackit]

I guess harmonics could affect neighbor's power. I'd sure be surprised if it was in any sense significant. Your single phase transformer has only a magnetic connection to the primary line. You connect transformer secondary to 1 phase of the first motor, make it spin. Windings in the other phases become a three phase alternator. Again, their connection to the first phase is limited to what the magnetic field induces. I'd say especially if your neighbor is supplied by a different transformer, issues would be negligible. These homemade multi motor devices are notorious power wasters, and don't offer the torque better designs do. I've never seen one operate. An old electrician showed me one he had built. It wasn't connected at the time. I'm repeating information he gave me.

Willie

Thanks Willie for the info.

[WillieB]

I read somewhere a long time ago if a home made rotary converter is not balanced properly, it will send it's dirty power down the line to their neighbors. Is that true?

I guess harmonics could affect neighbor's power. I'd sure be surprised if it was in any sense significant. Your single phase transformer has only a magnetic connection to the primary line. You connect transformer secondary to 1 phase of the first motor, make it spin. Windings in the other phases become a three phase alternator. Again, their connection to the first phase is limited to what the magnetic field induces. I'd say especially if your neighbor is supplied by a different transformer, issues would be negligible. These homemade multi motor devices are notorious power wasters, and don't offer the torque better designs do. I've never seen one operate. An old electrician showed me one he had built. It wasn't connected at the time. I'm repeating information he gave me.

Willie

[tackit]

I have a used phase converter, a 7.5 I paid 400. It is for motor loads. If you want to use second hand machines, a phase converter makes sense. If buying new, buy single phase.

Three phase power is sometimes 240 phase to phase with two phases to center tap being 120 volts, the third phase to center tap is 208. This is called center tapped delta.

Another configuration is Wye with neutral. Phase to phase is commonly 208, any phase to neutral is 120.

In both configurations the middle tap is grounded.

I prefer Delta 240 because motors are usually built for 230 volts, and will tolerate 10% high or low. The low side being 207 leaves little wiggle room for voltage loss. Motors make more internal heat, and less torque on low voltage.

Dynasty is equally happy on single phase as it is on three.

Three phase motors make three phase power. If your phase converter is big enough for your biggest motor, you can use numerous smaller motors on it. It works best to start smaller motors first, then the biggest. Those smaller motors help the phase converter.

Primitive phase converters were homemade using a combination of small motors. The first needs a means to start it spinning. A rope wound around the shaft like an old fashioned lawn mower works. The first motor will be weak. supplemental motors come on line improving quality of three phase power.

Willie

I read somewhere a long time ago if a home made rotary converter is not balanced properly, it will send it's dirty power down the line to their neighbors. Is that true?

[WillieB]

I have a used phase converter, a 7.5 I paid 400. It is for motor loads. If you want to use second hand machines, a phase converter makes sense. If buying new, buy single phase.

Three phase power is sometimes 240 phase to phase with two phases to center tap being 120 volts, the third phase to center tap is 208. This is called center tapped delta.

Another configuration is Wye with neutral. Phase to phase is commonly 208, any phase to neutral is 120.

In both configurations the middle tap is grounded.

I prefer Delta 240 because motors are usually built for 230 volts, and will tolerate 10% high or low. The low side being 207 leaves little wiggle room for voltage loss. Motors make more internal heat, and less torque on low voltage.

Dynasty is equally happy on single phase as it is on three.

Three phase motors make three phase power. If your phase converter is big enough for your biggest motor, you can use numerous smaller motors on it. It works best to start smaller motors first, then the biggest. Those smaller motors help the phase converter.

Primitive phase converters were homemade using a combination of small motors. The first needs a means to start it spinning. A rope wound around the shaft like an old fashioned lawn mower works. The first motor will be weak. supplemental motors come on line improving quality of three phase power.

Willie

[ShieldArc]

http://www.surpluscenter.com/shop.axd/Search?keywords=phase+converter

This may help.

[ryanjones2150]

Good advice. I have little doubt that I will at least make an attempt to build my own from fabber-cobbled parts I can salvage from who knows where. It's a project off in the near future at the earliest though. Seems simple enough in theory. I also understand the current to not be nearly as smooth as true 3-phase, but apparently there are things to help smooth it out a skosh. But the time I get to it, I'll be more versed.

[willray]

New to the forums here and trying to get some advice re: replacing welders I lost in a fire, but, while I'm hanging around I might as well try to be useful:

Rotary phase converters are, or at least can be, trivially easy to build. The simplest is just a 3 phase motor with your single/split-phase 240 hooked up to 2 of the 3 power connections, wiring for your 3-phase output hooked up to all 3 power connections on the motor, and a lawn-mower pull-start cord wrapped around the shaft.

Also requiring essentially no work, if you want a push-button starting rotary and don't feel like cobbling together the electronics, you can purchase one of those "static" phase converters, and hook it up to a spare 3 phase motor. The "static" converters are nothing more than the start circuitry from a rotary converter, and when you use one on a piece of equipment, you're essentially turning that piece of equipment into a rotary converter. Instead of hooking it up to equipment, hook it up to a spare, larger-HP motor sitting in the corner, and voila, rotary converter.

That being said, don't bother hooking up an inverter-powered welder like the dynasty to a phase converter. They don't need 3-phase input, and other than conceptually /maybe/ being able to pull slightly more power from your single-phase supply if you use an RPC to feed their third input, an inverter power supply isn't going to function any differently on single phase 240, than on 3 phase from an RPC.

[Tinker Joe 2]

Ryan, if one has the three phase motor and the electrical box and a lot of things in there that I don't fully understand he could build one but its over my head to build one, few little problems that I did get fixed but for what I paid for the American Rotary think it was 750.00 they were super to deal with, my thoughts, Joe

[Synchroman]

I have a Rotary Phase Converter that I built up myself fro a 7.5 HP Baldor 3 phase 1,750 rpm motor and the other various components needed. At idle, it draws 14 amps with a power factor correction capacitor and approximately 20 amps running a 3 hp milling machine. I understand that for motor horsepower, you have to de-rate the rotary phase converter about 1/3. Running a welder and a compressor would be quite a load. You would need to consider the starting amperage draw of a compressor. Also, you would need to know the average current draw of the Dynasty and add that to the draw of the RPC and size accordingly. For the record, I have heard that the two most difficult tasks for a Rotary Phase Converter would be a welder and a compressor, since they both have a starting surge and it's difficult to tell what your settings will be on the welder at any given time.

I guess we need a bit more information to determine the size o RPC needed.

[ryanjones2150]

So, Joe....what do you think about that converter your buddy built? I'm interested in maybe building one.

[MAC702]

A "high leg" of 208V is for that high-phase-to-neutral. You should have a 240V phase-to-phase voltage on that Delta-connected transformer. I'm not a transformer expert, but as an electrician, I'd call it a 240V system, not a 208V system, which is a term I would use for a Wye-connected 120/208V transformer.

And, yeah, I'm jealous.

[piniongear]

I have an American Rotary phase Converter to run a 1/4" x 10 plate shear and press brake.
For the air compressor you will probably want to go with a ADX series, On hydraulic equipment and hard starting air compressors you need to at min double the size of the Rotary phase converter of the biggest motor, that only leaves 5 Hp left to run your Dynasty.
The 15 Hp converter sounds about right to me.
I have the 40 hp phase converter to run my stuff, it never hurts to have a little extra, there are things that can affect the performance of the phase converter such as incoming power, at certain times of the day the voltage might drop a bit, you might be sharing a transformer with neighbors that pull power away.

In my situation, I had to have the power company install a bigger transformer because it was undersized for the power I was drawing, unlikely but possible, you might have a 208 volt transformer and not a 230 volt.

One thing I will say about American Rotary is that there customer service was excellent, they helped me determine that I had a transformer that wasn't up to snuff so they helped me boost up the made up phase until the power company installed the right transformer, we then had to rebalance it back down after the new transformer, they talked me through everything.
That was worth a lot to me.

Good points all. My transformer located on the pole serves my house alone. No one else has 3 phase.
I have a Delta wired set up with the 'High Leg' being 208 volts. So I assume that transformer must be 208 volts.
I run the air compressor 24/7 so that means the converter would also have to run 24/7.
Since I have the new single phase 5HP motor it makes sense to just run single phase. Ditto for the Dynasty and as Broccali suggests, the Dynasty will not know the difference.
That leave the smaller HP items to run off the converter.
I think I will wind up buying an American Rotary 7HP model and I am leaning towards the ADX series.
Thank you,
Perry

[Tinker Joe 2]

I have an American Rotary phase converter, 10 years of use and only had to replace on capacitor, its a 5 HP and I have a homemade one that a friend of mine built, it on the tube "meyoucajun1" if not its on "meyoucajun" I have loaded up that American and it will take it, they are great to deal with, could have got three phase and guess I should have but, 5,000 for a 30' pole instead of the 25' one more wire and a transformer, I will keep my cash.

[Broccoli1]

Good point Aeronca41..
I will talk to Miller but I think I have decided to run the D200 off straight single phase power. It will be a simple rewire at the new place and I have the pigtail already made up.
Perry

the Dynasty won't even know the difference on Single Phase.

[Portable Welder]

I have an American Rotary phase Converter to run a 1/4" x 10 plate shear and press brake.
For the air compressor you will probably want to go with a ADX series, On hydraulic equipment and hard starting air compressors you need to at min double the size of the Rotary phase converter of the biggest motor, that only leaves 5 Hp left to run your Dynasty.
The 15 Hp converter sounds about right to me.
I have the 40 hp phase converter to run my stuff, it never hurts to have a little extra, there are things that can affect the performance of the phase converter such as incoming power, at certain times of the day the voltage might drop a bit, you might be sharing a transformer with neighbors that pull power away.

In my situation, I had to have the power company install a bigger transformer because it was undersized for the power I was drawing, unlikely but possible, you might have a 208 volt transformer and not a 230 volt.

One thing I will say about American Rotary is that there customer service was excellent, they helped me determine that I had a transformer that wasn't up to snuff so they helped me boost up the made up phase until the power company installed the right transformer, we then had to rebalance it back down after the new transformer, they talked me through everything.
That was worth a lot to me.