Rotary phase converter's

Hi all, after many many years of being spoilt with 3 phase points all over the place, i am moveing to a house that only has single phase!!!!! i am deeply miffed about this and enquired with the local leccy people if they would install 3 phase so i could run some wood and metal work machines, yes indeed they can but i would need to sell the kids and both kidney's and all the machines.
so are rotary phase conveters anygood for 3 phase bench saw's and thing's like a 8hp myford lathe? i want to get a 10 hp one and have a dist board installed, i do understand i cant have more than 1/2 machines going at the same time but that isnt a problem, i also want to run a welder and large compressor and about 6 other machines, anyone got first hand experiance of rotary converters?
cheers chaps

rotary vs solid state

Howdy, can't say for the UK, but here 220vac 60Hz solid state three phase converters don't seem expensive. Here's a 240vac 1ph in 3ph out at 10hp VFD for $560 US: X200-075LFU. It looks like VFDs are cheaper than simple converters! It must be build volumes... Your 50Hz input shouldn't make any difference, given how VFDs are built. G.H <<<)))

You probably won;t be able to find a 15 HP motor that runs on single phase to say run the phase converter. I just took a guess.

Remember that you need much more than 746 W * 10 for a 10 HP motor. You have to be able to start it. I did a quick look and came up empty.

Lots of motor useful stuff, I think: https://www.electro-tech-online.com/custompdfs/2012/10/8_uid121420091225102.pdf

I real generator (natural gas) if your home supports it, might be a better choice. Then Diesel fuel. Possibly Propane.

Not your locale, but I was right. A 15 HP phase converter for a 10 HP load. See: **broken link removed** But, it does say a Lathe up to 7.5 HP.

And here is a little blurb about sizing: https://www.northamericaphaseconver...-converters/?gclid=COGPrPrLkLMCFUWo4AodalMAhQ

A FAQ: https://www.electro-tech-online.com/custompdfs/2012/10/QA20ROTARY.pdf

And a burb as to how they work: https://en.wikipedia.org/wiki/Rotary_phase_converter

And cheaper than a generator.

It looks like electronic ones are available too with a competitive price: **broken link removed**

My general comment might be, but I cannot back it up, is that the rotary phase econverter would be the best choice to be distributed to a bunch of machines and a solid state VFD would be appropriate for single machine control and they could be usedin combination. So a solid state VFD would be a really nice way to get a variable speed lathe, mill or drill press and all the parameters would be tailored to the particular motor.

I have been using this type of phase converter for decades and they are a whole lot cheaper.
https://www.waterfront-woods.com/Articles/phaseconverter.htm

Well I have had this thread here since November of 2009 relating to building multi function phase converters and its gotten about 28,000+ views since.

Apparently you were never one of them.

https://www.electro-tech-online.com/threads/3-phase-converter-schematic-miller-system.100563/

One other thing to remember when it is stated that the idler needs to be larger than the sum of all the driven motors is that that applies when all the driven motors are driven under load at the same time, as might happen in an industrial shop.

In a one-man shop, that is probably unlikely. So, if your tool motors are allowed to idle while you use your biggest tool, they effectively add to the power available from 3-phase and your rotary converter per se does not have to be larger than that largest tool motor. It is just something to consider.

I was also told that a "big iron" motor (i.e., older large frame) will work better as the idler than a newer, small frame motor of the same hp rating. I have not confirmed that, as I had no choice when I built my converter almost 30 years ago and used a small frame Baldor 5hp.

John

thanks all food for thought! i have a pre built rotary converter in mind but have never used one as i have been lucky enough to have 3 phase up untill now!

cheers
jason

You can get 10hp sngle phase motors, whether your domestic supply would supply it and your house without blowing the cutout is another matter.
I have a little myford and a trident mill as well as a bandsaw and other small machines, with little 0.75kw motors, all the machines run off a single phase inverter, single phase inverters produce 3x240v 3 phase, some motors can be re-connected to work off 3x240 rather than 415, its a more practical way for smaller machines and a lot quieter, I cant run all my machines at once, but I can control the speed and direction easily.

Yep a lot of it will come down to what exactly you are powering and what the device itself does.

For me having a stock three phase powered mill and lathe would be my excuse to go with VFD units but for higher HP stuff (5 Hp and up) like air compressors or rotary unit to power a three phase welder I would stick with the good old capacitor and voltage sensing relay based systems to power each device individually.

The problem I and most everyone I have ever built my converter units for has had the same problem. A good quality 10 HP single phase motor will cost between $700 - $1000 whereas a good used 10 HP three phase motor goes for $50 - $150 or free if you know the right people in a industrial facility.
Whats worse is once you pass the 10 HP level its nearly impossible to get any single phase motors and the very few, if you can find one, will cost outrageous amounts. The biggest one I have ever seen myself was a 12.5 HP unit that retailed for something like $2000!

The self contained converter system I have on my 15 HP commercial air compressor has at most maybe $200 worth of parts on it.

However as mentioned earlier there is the other problem that goes with big electrical equipment. Do you have the service capacity to power the stuff?

the house we are buying was infact a old victorian hunting lodge, that for the past 50-60 years has been run as a country house hotel, it should of had 3 phase and i have no idea why it dosnt, but if there is enough capacity to run the massive commercial kitchen then there is plenty to run a workshop! the kitchen is going to be ripped out anyway.
i wont be running more than one machine at a time as there is only me there in the shop! i will dig out some pics of the place latter! it even has three fishing lakes in the grounds!! perfect.......
plus 38 acres of mature woodland.