My Rotary Phase Converter build

Yeah, but the house is, and I happen to have a family in mine.:eek: (and one that I certainly care about;))

Can't quite figure out your response Alan :huh: ... Protecting the wiring was never questioned, I hope it doesn't appear that I'm advocating some un-safe practice :wave:
 
John,

Not much to figure out, I was only stating that the breakers do protect the circuit, in case there is a problem with the machine, so that you won't have a problem beyond that, in the house. So, while it might not protect the machine, the bigger protection is in regard to the house, at least as I understand it.

I could be wrong, I'm no electrician, and why I had a friend help me wire mine.
 
OOPS!! Never dug through the box of capacitors till today. Realized I was missing some. Dug down deeper and found these two monsters! Had to rearrange a little bit to make them fit but they fit. I need to install the ground bar, hook up two or three wires I didn't have spade terminals for and it's ready to go.

wiring3.jpg

I finally gave up and bought the 15hp motor since I couldn't find a 10hp any where, much less as cheap as this one. Man is this thing huge too! I thought that old one I restored was big.

idler.jpg

Hoping to mount it to the wall and wire in the panel tomorow and fire it up.

Jeff
 
She Runs!

RPC is up and running. I finished the wiring Saturday and mounted it to the wall. All that was left was to connect the motor and connect it to the main panel. Moving the motor in place was no small task! That is one big motor. I rested it on a one of puzzle mats I had. I could slide it then but once I got this far I ran out of steam.

I still need to build a guard for the the motor shaft. But I have great idea. Since this is a c-face motor I can just cut a round piece of ply, cut a hole in the center and insert a piece of PVC with a cap on it. Then bolt it to the face of the motor. Simple and cheap.

Today it's raining so I got to work on the RPC this morning. Got everything connected. Turn on the breaker and no sparks or Ozone. I hit the start button... nothing. Not a sound. Quick look around and I see the problem. I connected the line to the wrong side of the relay so there is no power to the start button/circuit.

Move the wire and hit the button. There is loud thump as the relays trigger, the idler motor starts spinning and comes up the speed and then suddenly there is moderately loud vibrating sound. I tried it a couple of times and it only happened when the motor hit speed so that narrowed it down. I fired it up and quick touched each relay with a screwdriver and found the one that was vibrating. Checked my diagrams and I had a wire on the potential relay connected to the wrong terminal. Moved that tried it again. Motor just hummed. :bang:

Stop to think a minute and had an idea. I started the motor spinning with my foot, hit start and away we went. We have a working RPC. I remember that Bruce said I probably needed to add more start caps for this bigger motor and that was it.

I have not checked the voltages yet or tried to balance it out. Just happy to see it run. Time for lunch and then I will check my output and see what I am up against.

mounted1.JPG mounted2.jpg

I had planned to add remote start switches in at least a couple of places around the shop just for convenience. After hearing how quite that idler motor is I am going to have make sure they have run lights or add them to the circuit! That motor is so quite that after a few minutes it's just going to be background noise that I will not notice and I will leave it running.
 
man jeff! i leave for a coupla weeks and you go and build a convertor:eek: .....way cool! i`m looking forward to the actual build story once you know how it runs.......i think you`ll be able to save quite a few folks substantial sums of money as long as they`re comfortable messin` with `lectricity.......tod
 
I guess I need to go back and reread, but here the question.

Does it only require one motor? Are you producing 3phase yet?

This is a really great project because so much 3Ph stuff comes on the market that is priced right because no one has 3ph in the small shops.

Thanks for posting all this...
 
Does it only require one motor? Are you producing 3phase yet?

Yes and yes.

Basically 3 phase power is 3 hot wires of electricity. You have two coming in your house as 220v, so your 2/3rds of the way there.

The idler motor is a 3 phase motor. 3 phase motors will run on single phase (2 hot wires) once you get it started spinning. So through some capacitors and some switches and some electric magic that is what the phase converter does. It starts the 3 phase motor on 1 phase power.

Now with the idler motor running, the 3 leg is working as a generator and producing electricity (amazing isn't it??). Now you just take that generated leg, add it to your existing 2 legs in you house and Waa Laaa! 3 phase power!

Simple as radar isn't it? :rofl:
 
It's up and running and balanced out. For those of you that understand all this here is the results.

Voltage across A- C= 226vac
Voltage across A- B= 236vac
Voltage across B- C= 235vac

Amperages were
10.5 - 20.5(generated leg) - 15

Seemed a little off to me but Bruce assured me that was good numbers. He also said I could be able to fire up a 10hp motor with ease. I haven't run any power around the shop yet. So I haven't put a load on it, thats this weeks project. But man am I glad to have this much done!
 
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Congrats, Jeff!:thumb:

Didn't seem as painful as I thought it would be....

Look forward to more of the details as far as schematic, parts list etc., if they can be made available.
 
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Well done, Jeff. :clap: Your explanation of what an RPC does finally made the concept make sense. I've seen one in action, and understood the basic "get three phase out of single phase" idea, but now I know how the pieces fit together a bit better.
 
Greg, plans will be forth coming. Bruce just wanted to prove it first and we found a typo in the plans. Kept adding Caps to the system and the amps kept dropping instead of going up. After I triple checked the wiring Bruce finally discovered he had reversed the labels on the plan. I was adding the caps on the wrong side. Reversed the wires and it jumped up close to what we wanted.

His next trip down he is going to "tweak it" it some. This is the first 10hp model that he designed and I think he just wants to test it some and see if he can get some more performance out of it. :dunno: Said he would bring some additional caps and just see what it could do.

I don't understand the fine points of it. I just know it does what it is supposed to do and that I can move on to finishing up the the tools and then get back to wood working.
 
Hmm ... that explanation really clarified things for me, too. But it also raises another question ... Is the draw combined, then? So the two legs that you put on your 3ph load PLUS the draw that the idler motor pulls using its two legs?

I think that makes sense ... if your RPC is drawing 10amps on your two single phase legs and your load is drawing 10amps on those two legs as well, you're drawing something like 1.333~ times what the 3ph load would normally draw on true 3ph, right? That at about 70% of the rated power, yes?

I'm trying to understand the compromise that phase conversion is compared to true 3ph. It draws a little more amperage and runs with a little less power, right?
 
Jason, I am not totally clear on all the details on this. But from what I understand you're generating true 3 phase. As far as I know there is no difference and your getting full power from the motor you're driving. The difference is the voltages are not all exactly the same. Thats where the balancing comes in. You want to get them to within 10% of each other. 5% is considered very good from what I gather and I think I am right at the 5% mark.

One thing that bothered me was these high amp readings on the idler motor leads. I was thinking that this must be costing me a lot to run. But when I put the amp meter on the two lines from the single phase panel to the RPC I was surprised to see that the idler was only drawing 2 amps! Bruce told me that the amp readings on the idler are what used to be called a false readings. I didn't quite follow it all and honestly didn't try too.

But (as I understand it) your motor, not the idler, is going to determine the amperage it draws, not the RPC. Assuming you can generate enough amperage on the generated leg, the motor is going to draw what it needs. So, I don't think the motor is going to see any difference, except the difference in voltages on each leg.

Jeff
Talking over his head here.
 
Jason, I am not totally clear on all the details on this. But from what I understand you're generating true 3 phase.

Jeff, I don't think thats quite right -- though I may be wrong, its happened often enough before. You're generating a third phase, but the other two legs are single phase, adjusting the voltages with caps is how you're imitating three phase. Now if you use a big drive motor to run your idler, and its not connected to the single phase line, that would be true three phase, and you wouldn't need all those caps. But if you had a big single phase motor to run the idler, there'd be no point to this exercise, as you could just install it in a machine.

As a bit of background, a capacitor will essentially delay the Ac slightly. You're using them to nudge a bit of current 30 degrees at 60 hz or by about 0.0014 seconds. The part I'm not quite clear on is why the voltages end up so high, but I believe its somehow related to it not being true three phase.
 
WHOOO HOOOO! Another one done!

I OFFICIALLY have 3 phase in the shop now! Man is that a relief. It means progress can return to the Bandsaw and TGP and get them finished.

I was going to include a photo of my Queen City Grinder running to prove I had 3 phase. But I under estimated the speed of the flash on the camera. :eek: Looks like it is sitting still. But that buff is floppy and normally doesn't stand up straight so you just have to trust me.

finished3.jpg

Here is the final setup. 100 amp panel on top. RPC with the green light on (means it's running) under that. The 15hp idler under that. I still need to be a shaft guard but I turned it away from everything for now. But the thoughts of 15hp grabbing something scares me. I doubt your going to stall that out till it has you in some serious hurt!

Over on the right is a 3 phase disconnect panel I bought because it has fuses. I need something to protect the output line running across the shop. I found this on EBay for $20 shipped to my door. Couldn't touch anything else for less. Of course I spent $150 at Lowes today on wire and related items to get the wiring around the shop. Man copper wire is high!

finished2.jpg

For everyone that wanted to see the works, here is the rats nest. Now that I see it wired up I would have turned some of the components and mounted others in different places. It doesn't hurt anything it just looks like ..... well ...... bad.

finished.jpg

I have wired dropped to the Jointer and Bandsaw. Thats what I have been waiting on. So I am going to concentrate on the jointer first. Get it up and going since it is really needed. Then will work on the bandsaw. But it needs a fair amount of money thrown at it now.

Jeff
 
Fantastic job Jeff, I think it is a fairly neat package, and well done.

The "Rats nest" is not that bad, in fact, I think it is not really "Ratty" at all.

Can't wait to see some of that old arn in action!

Next time, to take an action shot of the grinder, stick a piece of steel in it, and get it sparking, then take you picture!:D :wave:
 
Great job, Jeff...

I'm sure you've inspired a lot of us to get 3ph in our shops and take advantage of some of the bargains on older tools and even new motors...

Thanks a lot for posting this, and again...congrats!
 
Great job Jeff! :clap:

Roughly how much would you say it cost to build your RPC? I'm sure no matter what it was, it was alot cheeper than having the power co. run 3 phase to your shop.
 
Roughly how much would you say it cost to build your RPC? I'm sure no matter what it was, it was alot cheeper than having the power co. run 3 phase to your shop.

Tree Phaze ;) is not available at my house so it was the only way to go. I meant to keep up with the cost and really thought I could build it for $200 but I think I am closer to $250.

Now, you can build one much cheaper. As I have said before Bruce's design is top line. His is built right and should run forever and be safe. He has a motor overload for idler motor and a potential relay that bypasses the start caps as soon as the voltage is up. Most designs are not nearly as sophisticated. Those two items add $100 to the cost easy. But I don't worry about the thing catching fire of blowing up either. ;)

You could probably build a very basic one for $150. I don't see building Bruce's for less than $200. Of course if you had time to shop EBay for the deals or a good source for used motor relays and enclosures you save some money.
 
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