230v to 415v rotary phase converter

[OldLes]

Not sure if this is the correct section for this, but here goes.
I spent about four months of my spare time developing the above. No transformers, and it works.
I picked up the idea from a Utube video by a guy down under who seems to have fun destroying washing machines and all sorts of crazy projects. Obviously not stupid though!
I made a video which you can see here:---
https://www.vimeo.com/47988196
In view of all the time I spent developing it, I am trying to sell copies of "The Plans" on Ebay (UK), but I welcome viewings and maybe some comment.
OldLes.

 

[panic mode]

this is nothing new, using auxiliary 3-phase motor and start/run capacitor to produce 3phase was around for very long time.
i don't see who would want to pay for plans for it as this is public knowledge. even if this was not the case, i don't see
who would spend money for plans, only to have to shop for parts and build it himself when
one can get attractively priced off the shelf product designed just for this.

unless one happen to have all those parts laying around, i see little reason to build it.
i see there a 3-phase motor, five contactors, five capacitors, timer and several hours to put it all together.
even raw material cost (not taking cost of labour to wire it up) is more than the price of modern electronic inverters.

electronic inverters are cheaper, lightweight, compact, silent and also have plenty of
features that make them far more flexible to use. usual goodies are different modes of operation,
run current limiting, speed control, inrush current limiting etc.

as an example here is a comparable 3HP drive that can be powered from 230V single phase.
http://www.automationdirect.com/adc...ts_(115_-z-_230_-z-_460_-z-_575_VAC)/GS2-23P0

just a thought...

 

[cowboybob]

OldLes,

Welcome.

I'm impressed with your system. I can fully appreciate your efforts and the results (FINE lathe, by the way).

Don't know about selling the idea/plans/etc. on EBay, but what the hey, give it shot.

I take it you're on a farm (rooster crowing in background - very nice touch but I bet you didn't even notice ).

I've got a friend (well, had a friend, he died last year. Crazy as a loon) who did a similar thing for aerators used in horseshoe crab holding ponds.

Very neat looking job. I will say, however, you scared the boo-daddy out of me poking around in the box with all that juice flying around (even if the main switch was off).

Good luck.

CBB

 

[OldLes]

Cowboy Bob, no, not on a farm. Neighbours have cockerel and chickens that wander everywhere, and at 3:00pm I didn't notice it. Now at 05:am, I could strangle the damn thing. Glad you liked the RPC, and the lathe.

Panic mode, I don't know if you read the title, but it is 415V output. Here on the eastern side of the big pond, all our three phase supplies are of that voltage. Commercial RPCs still sell well over here, especially to disillusioned inverter owners. However, both these RPCs, and the static inverters available, all have big, heavy transformers to get the output voltage required.
All the commercial RPCs I have looked at use the well known delta wired circuit such as has been around, as you say, for decades.
Now if you can point me to a 230V single phase input, 415V three phase output RPC without the transformer, I would be interested to know, maybe I can learn something else.
The inverter you link to is 230v in, 230v out. They ARE available with 415V output, but MOST of those I have seen are intended for three phase input by the original manufacturers. I have seen them "modified" by covering up the third input terminal, and sold with the original output specification still shown, without any NECESSARY de-rating.
I am also aware of some which were sold by the manufacturers as 230V in, 230V out, both with the hidden third input terminal, and the software manipulated to get the 415V output.
I am told it can't be done, but I have tested one and seen it. Still sold with the original output specs, other than the 230V being overwritten by 415V.
Don't get the idea I am expert on this, I am not, but by having a reasonable knowledge, and testing and documenting many failures and modification, I have something I am proud of, and which WORKS! Only time will tell if I succeed in "selling the plans", but I have already been asked to supply a kit. I am thinking about that, but if I do, it is more time I can't spend with my motorcycles.
OldLes

 

[panic mode]

i don't know about needs and market prices in UK. i only wish you luck with this.
but why it has to be 415V? all three phase motors i've seen are configurable why/delta and you don't need transformer.

 

[OldLes]

Nowadays over here, most new motors are dual voltage, but if you acquire an old industrial machine (such as my Harrison L6 lathe) you only have a 415v connection system.
Of course, in many instances, you can dismantle the frequently star wired unit for 230V delta operation, but whilst some are not too difficult to convert, some are just about impossible. And then many are already delta wound, and so not convertible, as are the many motors wound as 415 / 750v, intended originally for star / delta soft start purposes.
OldLes.

 

[dieselmaker]

Hi there from a newbie to this forum. I am dead keen to obtain/make a single to 3 phase unit. After purchasing 3 X 3 phase gensets that were not fit to be marketed I have gone back to the plan of 3~4 years ago. A converter!! I would like to see/buy/beg etc the plans for this as it has 1 feature I have not seen but would dearly love to have. @30 in and 415 out. I have several small 3 ph motors and not one has access to the neutral. Any help in locating these plans much appreciated guys. Thanks from Chris.

 

[tcmtech]

https://www.electro-tech-online.com...r-schematic-miller-system.100563/#post1120756