Thread: 2hp phase converter up and running!

I probably should point out the $3800 was the cost to me as I can claim back the GST..Also had freight on top of that...The total cost was around $4400

Also it was a demo model meaning it was used at field days, so even though I got the full three year warranty it was not brand new out of the factory..

Just have to wait now for a cheap surface grinder to come up for sale close by..

Hi All, I have just been following with much interest the discussion on home brewing a RPC in Australia. I have for some time been researching this and asking as many sparkies as possible if they have ever had any experience along these lines and so far to no avail, although a few have taken it on board and are chasing info if they can locate it! I have seen a good deal on the Practical Machinist site, but felt that in Australia a transformer might be needed to step up 240 to 415v and to overcome the lack of a second live incoming line as I gathered the U.S. widely uses a split phase system with both lines hot. It was great to find this discussion, and really great to see a wiring diagram listed, - I don't know if it is just me or not, but I cant click the thumbnail for the enlarged image to download. When I click that image the screen goes black and I have the spinning paddlewheel telling me to wait a bit, but no larger picture downloads. All the others work ok, so I'm wondering Fossil if you could perhaps try to upload it again, in case the link has broken for some reason. If it still works for everyone else, I'll try on my wife's PC, (mine is a Mac, but works fine for me normally). I will be out till evening tomorrow, but will look again when I can.
Keep up the great work and congratulations on your perseverance in making a successful RPC in spite of the fact that "it couldn't be done". I want to acquire some wood and metal working machines to keep myself out of mischief in my rapidly approaching retirement years, and I mostly get told of all the advantages of VFDs in generating 3~ from single, (you've probably heard all this too) but while they do have their good points, running welders, especially the kind that use 2 phases of 415v only, running multiple motors simultaneously and low acquisition costs are not among them.
Cheers
Rob

Hi Rob, and welcome from me to the forums.

The thumbnail link works for me, but here is a direct link to the schematic for you.
http://www.woodworkforums.ubeaut.com...1&d=1223975147

Good luck with your RPC build!

Hi,

I've been researching these rotary phase converters for quite some time now and just today I found out in Australia we need a 240v - 415v step up transformer. Just wondering what would be the cost for the transformer?

I want to run a welder from it so the 415v is important for me.

Just trying to work out if it would be worthwhile building a rotary phase converter that outputs 415V.

Thanks

Suppose the first question is what size welder do you want to run??

It's a 400 amp mig. Though i'm sure i'll find other uses for it in the future.

There are old stick welders out there that operate on 240, 415 and 480V.. They can be used as a transformer feeding 240V in and you get 415V out, then use the 415V to feed the phase converter..

Some reading here -->> Rate my RPC - Practical Machinist - Largest Manufacturing Technology Forum on the Web

and here -->> Aussie RPC project. - Practical Machinist - Largest Manufacturing Technology Forum on the Web

cheers will look into that, should be able to pick one up for almost nothing.

Any reason you went for a commercially bought converter rather than building your own?

Has anyone priced getting three phase on at domestic premises?. I'd be interested to know if commercial rates have to be paid like in the past. I've asked two sparkies so far and had estimates of $400 and $2000.

Originally Posted by Graziano

Has anyone priced getting three phase on at domestic premises?. I'd be interested to know if commercial rates have to be paid like in the past. I've asked two sparkies so far and had estimates of $400 and $2000.

I think it all depends on what is required.... For me to get it, Ergon had to run one wire about 400m and replace the transformer with a three phase one.. I priced it about ten years ago and was told by Ergon $12 000.. Then there is shed wiring and service pole wiring on top of that....Three years ago when I again looked into it I was told $20 000+.

Originally Posted by Com_VC

Any reason you went for a commercially bought converter rather than building your own?

Safety being one.. Versatility being another and also I did not know about the 240V/415V welder/transformers back then..

The phase converter I have tries to balance the voltages with varying loads...

Home made ones as they only have one set of capacitors are only balanced at one load..

You never get a proper 415V between each phase with a phase converter, the voltages vary depending on the load..

Has any seen the website

www.Unquie3phase.com

I have the dvd from them but have not really followed through too many other projects working on.

Not too mention needed to really swat up on the subject matter.

But very impressed with some efforts by fossil.

Also envious of the professional model from phasechanger.

Its all still very foreign to me at this stage.

Cheers

Pulpo

Is there a specific type of motor I should be looking for. I've settled on a 10HP motor, it's slighly undersized for the welder at full output but I won't be using it past 250A.

I figure i'll get the motor first and then sort out the rest later.

Thanks

Originally Posted by Com_VC

Is there a specific type of motor I should be looking for. I've settled on a 10HP motor, it's slighly undersized for the welder at full output but I won't be using it past 250A.

I figure i'll get the motor first and then sort out the rest later.

Thanks

The US people say with the home brew phase converters you need a lot lot bigger idler motor then the maximum sized motor you will be starting... Reasons being a 10 horse power motor might suck 50 amps on startup and your idler motor cannot supply that much power in one go...Welders are bad for surging.. The commercial IC controlled units with multiple capacitors get around around this by using their bank of capacitors, switching them all on to handle a surge...

Originally Posted by Com_VC

Hi,

I've been researching these rotary phase converters for quite some time now and just today I found out in Australia we need a 240v - 415v step up transformer. Just wondering what would be the cost for the transformer?

Recently I priced a step down autotransformer. There was one mob in Perth that quoted me about $400 and another in NSW that was $1000 for a 15kva 480-415 volt transformer. This might give you some idea what a 240-415 volt step up transformer might cost. Note: autotransformers are significantly cheaper than the isolated type.

I have two phase at our new country property and I am entertaining the idea of converting 480 volt 2 phase to 415 volt 3 phase.

I have been looking at the Eurotech kits (some information can be found on Ebay) and these are significantly cheaper than buying a commercial unit. If I source the components myself it will be half as much again. Even if I buy the kit it will be 80% cheaper than getting Spaznet (SP Ausnet) to hook up 3 phase.

No doubt if did something similar to Fossil's design I could build one cheaper still. However I do use my machines for work purposes so a phase converter will be tax deductable.

All the Eurotech representatives tell me I shouldn't have a problem getting the kit to work. Anyone built one of these?