Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
(OP)
This is a new thread from my initial 'Phase Converter question - 1ph to 3ph'. (To all those that answered thanks very much). Instead of continuing that thread I thought it best to start a fresh one.
I have more data now. Our 3 phase 7.5hp/5/5kw coffee grinder's motor plate is at this link so you can see the specs on it.
I am going to run the grinder on house current (IRELAND) of 230V/50HZ.
The load on the motor will be steady and there will only be this one piece of equipment being serviced by the converter/inverter.
One friend, who runs a lot of 3ph equipment says to buy an INVERTER to change the power from 1ph to 3ph. He says the power delivered will be more steady and my motor will last longer. Two or three other people say the exact opposite. They say the INVERTER will have a lot of distortion and won't be as 'harmonic' as the ROTARY/DIGITAL converter.
Another says I need a ROTARY PHASE CONVERTER because if the input to the INVERTER is 230V I'll only get 230V coming out the other end.
Another says I should look into a DIGITAL PHASE CONVERTER as it is better than the ROTARY even though it costs about £400 more. He says the DIGITAL converter is quieter and delivers more even power.
The ROTARY PHASE CONVERTER company says they're the best way to go.
The DIGITAL PHASE CONVERTER company says they're the best way to go.
I'm completely confused. What's the difference between ROTARY and DIGITAL converters, and which would you purchase given the information provided? And if you lean toward the DIGITAL CONVERTER is the higher price justified? If you need additional information please let me know.
Thank you in advance for your insights!
William
I have more data now. Our 3 phase 7.5hp/5/5kw coffee grinder's motor plate is at this link so you can see the specs on it.

I am going to run the grinder on house current (IRELAND) of 230V/50HZ.
The load on the motor will be steady and there will only be this one piece of equipment being serviced by the converter/inverter.
One friend, who runs a lot of 3ph equipment says to buy an INVERTER to change the power from 1ph to 3ph. He says the power delivered will be more steady and my motor will last longer. Two or three other people say the exact opposite. They say the INVERTER will have a lot of distortion and won't be as 'harmonic' as the ROTARY/DIGITAL converter.
Another says I need a ROTARY PHASE CONVERTER because if the input to the INVERTER is 230V I'll only get 230V coming out the other end.
Another says I should look into a DIGITAL PHASE CONVERTER as it is better than the ROTARY even though it costs about £400 more. He says the DIGITAL converter is quieter and delivers more even power.
The ROTARY PHASE CONVERTER company says they're the best way to go.
The DIGITAL PHASE CONVERTER company says they're the best way to go.
I'm completely confused. What's the difference between ROTARY and DIGITAL converters, and which would you purchase given the information provided? And if you lean toward the DIGITAL CONVERTER is the higher price justified? If you need additional information please let me know.
Thank you in advance for your insights!
William





RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Then let's talk about a digital inverter.
We generally make a distinction between an inverter and a Variable Frequency Drive.
An inverter generally puts out set frequency and a set voltage. If you run a motor on an inverter the inverter will have to handle the starting surge. Either it will be more robust to handle the surge or it must be oversized or both.
Actually the same holds true for the rotary converter. Some rotary converters may be connected to deliver double voltage, but it will have to be twice as large. The other little hitch is that if the rotary machine is used as a voltage doubler, that is what you will get, double voltage, 460 Volts, not the 400 Volts that the motor wants.
The VFD on the other hand, is optimized to control and protect a motor.
Sure it is a type of inverter but if varies both the voltage and the frequency.
That gives you the advantages of speed control and avoiding starting surges.
VFDs are readily available and probably a lot cheaper than an inverter, even before you start oversizing the inverter.
Think:
Transformer, 230 Volts to 400 Volts.
VFD, avoid the starting surge.
Starting that motor DOL on either a rotary converter or a standard inverter will develop a starting surge at 230 Volts of 120 Amps to 150 Amps.
A VFD may be able to keep the starting surge down to 25 Amps.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
A "Digital Phase Converter" is a nebulous term with no official definition, but generally means something like a "Phase Perfect" brand of device. This works by taking in the single phase source and tapping off of it to power up a SINGLE inverter module, so it ADDS the third phase to go along with the other two. But the problem is, in a single phase source, the two "hot" lines are really opposite ends of the SAME phase, so are displaced from one another by 180 degrees. In a 3 phase system, the 3 phases are each displaced from one another by 120 degrees. So in digitally adding the "third phase" with an inverter, that third phase is neither 90 nor 120 degrees from the other two, its a compromise. Ultimately this slightly affects the efficiency of your motor, but is not as bad as with the RPC and because there is only ONE pole of an inverter, is less expensive than a VFD. It's also usually OK with powering up other loads on the same machine.
A VFD / Inverter drive converts your single phase source to DC and recreates the 3 phase as an entirely NEW source for the motor. The phase are balanced, the motor is soft started, the VFD typically comes with better motor protection than any other option etc. etc. Don't get excited about "harmonics" with regard to the motor, someone telling you that is all wet. Yes, there are some, but it's not a big deal. There are some serious issues worth considering IF you were running the motor at 380-480V, but not at 230V 3 phase. The down side of the VFD option, as I told you in the other thread, is that you have to double the size of the VFD for the motor (in you size range) and it can only be used for that ONE motor, you can't use it to power up other devices that are connected to the motor circuit, like other electronics, relays etc. So you often must get into the guts of your machine to separate the circuits and have the VFD supply ONLY the motor portion of it.
In my opinion the Digital Phase Converter may be the answer for your situation though.
PS: After reading Bills post, I may have to amend this vis-a-vis the 230V vs 400V issue. But I don't see where you ever actually STATED the motor nameplate voltage rating. What is it?
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
On the nameplate.
I'd go with the transformer to step up the supply voltage, then a use 400V in, 400V out inverter. You'll probably pick a used VFD up on ebay for £150 - £200 or so. Buy some extra capacitors for the DC link - you'll need types rated at 600V or greater. The transformer might take a bit more finding, or you might have to buy one specially: at that power rating it will be quite a big one.
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Re the digital add-a-phase converter.
If you supply the circuit with 120/240 Volts single phase, you can add 208 Volts to the center tap at 90 degrees and get true four wire delta out. (A combination of 240 Volts delta and 120/240 Volts single phase.)
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Further, the OP is stating that the inverter is £400 MORE than a rotary. This leads me to think this may be a full-on three phase inverter and NOT just an added single phase unit.
Can this motor be reconnected to offer 200/230V operation? I suspect it might since the plate actually states " Δ " what do you guys think on that? It would save the hassle of a transformer.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
I'm looking at a motor rating of 5.5 kW.
With about 80% overall efficiency that will be about 30 amps at 230 Volts.
On a total available service of 63 Amps it doesn't look good for DOL starting.
The effect of the staring surge of a 7.5 HP motor going DOL on 230 Volts is one reason I suggested a VFD.
The phase converter will have to have double the current rating if it goes on the 230 Volt side.
Over here in NEMA land, there are a lot of single phase transformers available in that size range. Not so many small three phase transformers available off the shelf.
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Expat: I hate to tell you this but I think you're... nutz to do this. A coffee grinder? You essentially have a machine that you run for a minute that is a monster not sized for your application or location. You are going to spend a fortune getting this to all work right. It's like you bought a semi truck to do daily deliveries of a crate of apples!
You should step back and re-assess the logic of this whole thing. I suspect a 1HP grinder will do a very nice job for you without all the phase crap and humming, house-heating transformers it won't need. Sure it will take a little longer but why would you care? Just make sure what you want to grind will all fit in the hopper so you don't have to babysit the operation closely.
Every boutique grocery store I go in has coffee grinders the patrons can use that munch large bags of ground coffee almost instantly that are surely less than a horsepower as they're just "plugged in".
I suggest you find a nice smaller machine that will be quieter, less of a space hog, and not require an acre for transformers and phase converters. Also it won't ultimately have your neighbors reporting you because their TV's reboot or they hear buzzing out of their speakers every time you fire up the monster. You will save a bundle of money by disposing of the non-optimal choice now instead of after you've been visited by pitch-forks and torches.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Would that I could. I'm a wholesale coffee roaster. Right now I run 3, 1hp grinders and I run them just about all day, every day, shutting them down for long periods to cool. It's just past 10pm here and my son is still outside grinding coffee. This is a huge bottle-neck for us.
To replace the grinders would run me about £2k each for an equivalent grinder.
Just this past Friday I ground all day but didn't keep up with my orders. This meant grinding 1/2 day Saturday and 1/2 day Sunday. All this grinding takes it's toll on the grinding discs. So when the grind quality deteriorates I have to remove the discs (the grinders are no longer made by the way) and send them off to a great guy in the UK to be sharpened. And sometimes he has to make me new discs when they are beyond sharpening. In fact I'm waiting on a new set right now. This downtime of one grinder puts more strain on the other two grinders and round and round we go. So I know I'm spending a lot to make this work but as my son likes to say, 'It has to be done'.
The grinder I'm buying will keep up and beyond which I need because of some new markets opening up for me. The grinder is costing me X. An alternative grinder, that I could just plug in and go on my house current would cost me XXX. So spending X or half-X to convert the power seems to make economic sense.
All that said I really appreciate all the comments here. With all the input I'm really starting to be able to get my head around this. It is starting to get down to choosing the best option. I think the best choice based on all the folks I've talked to and all of your comments -- and I welcome a correction as I'm less than a layman -- is to phase convert 230v 1ph to 230v 3ph and then use a VFD to go to 400v 3ph. To me this is great because it doesn't require more amps than I can deliver. WAROSS suggests I'd be pulling 25A at start.
My second option, the Digital Phase Converter, is the one I may go with for two reasons. 1. it seems simpler than option 1. The way I understand it, I plug in 230V / 1ph / 50hz into the DPC and out comes 415v / 3ph / 50hz with a soft start so that I'm not tripping breakers on start-up. And 2. I just can't seem to find an electrician here in the rural West of Ireland who can get their head around what I'm trying to do. The ones I've spoken with are great guys but their experience mainly extends to wiring-up a house and that's it. I know there is a guy, multiple guys, around here who could do this in a snap, I just haven't come across them. Hopefully I will.
So there is my long-winded explanation of why I'm doing something that seems nutty on the surface but hopefully this look behind the curtain explains my need.
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Admittedly, it might also be possible to replace it with a single phase unit, although its generally a less than optimum solution. That option will get around the issue of having to rewire the unit to split the VSD output from any control equipment that is fitted, although in order to start and stop it you'd probably need to do that anyway.
The other consideration is that there's no way around the 5.5kW size of the grinder. Whatever VSD you use will need a suitable supply for it, and if Ireland is anything like Australia, single phase socket outlets only allow a certain size (about 2.4kW here) to be powered from them. Thus, no matter what you do, there's modifications to the house wiring to be done, you'd likely need a 25A socket outlet (or get the electrician to hardwire in the VSD).
EDMS Australia
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
did not adequately paint the picture you just did.
Let's look for, perhaps, an out-of-the-box solution since it's very possible you simply cannot support that load with what you have as a domestic supply.
Do you have any idea how long The Monster would take to do a day's grind?
Got a picture of it and its motor overall?
Use the
Keith Cress
kcress - http://www.flaminsystems.com
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Winding Design and Motor Repair
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
The motor takes 10.8 Amps at 400 Volts.
Now bear with me until the end;
5.5 kW at 75% combined efficiency and power factor = 7.5 KVA
7.5 KVA at 400 Volts = 18.75 Amps single phase.
You need a 7.5 KVA, 230V:400V transformer.,
OR
Use an auto-transformer connection.
You will need a 4 KVA or 5 KVA transformer. 230V:230V. The output will be 460 Volts, single phase.
Then connect a VFD to drive the motor. The VFD will have no trouble driving and protecting a 400 Volt rated motor with 460 Volts supplied.
A 230:230 Volt transformer may be easier to find than a 230:400 Volt transformer.
I have done a lot of voltage adjustment for motors with auto-transformers, both single phase and three phase.
Others here have more experience than I in sizing VFDs for single phase supplies, so I will stand down now and let the others help you with the VFD sizing.
You are going to need about 40 Amps, at 230 Volts. I hope that an additional 40 Amps is available from your 63 Amp Mains Service.
By the way, if you can post an internal wiring diagram for the machine or a make and model number we may be able to help with the connections to power the control circuits.
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
This is the grinder. It will cut my grinding time by 75% (and this is taking the manufacturer's throughput claims and halving them).
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
It appears to have no other controls other than ON/OFF so a VFD is certainly a clean option.
With a 230V motor this is what a typical doubled (as Jraef states) VFD would be new:
230V 15Hp VFD
You have to add the cost of swapping in a more appropriately voltaged motor.
If you added the boost transformers as waross describes, kept the existing motor and used a 460V VFD this is what you'd be looking at:
460V 15HP
You have to add the cost of the transformers.
With either VFD you leave them powered up so there is rarely a big surge on your service and the neighbor's services who share your service transformer. You always leave the motor on. In fact you make it so the motor can never be turned off while the VFD is running it as that can harm the VFD.
Then to run the grinder you press run on the VFD and if it's setup correctly it will quietly ramp up the grinder motor with no shock to your electrical network and actually no mechanical shock to your motor or the bearings.
A VFD also allows you not to have a motor starter involved, which is not seen in your picture but must be there somewhere?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
As for coffee, I was of the understanding that the grind (including the timing of when the beans are ground) are critical to good coffee, I'd not like to think that the new grinder is faster but has less consistency.
EDMS Australia
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
All that aside, everyone has given me a lot of food for thought. Besides my #1 and #2 choices I wrote about above I'll look into the 230v 3ph motor option with a VFD.
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
But first check the shaft. Make sure that this machine doesn't have a special shaft.
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
You're looking for a motor with these characteristics, if you fancy going shopping:
4-pole
5.5kW
230VΔ/400V Y
132S frame
B35 foot-flange mounting
Most of the decent European manufacturers - Brook, ABB, Siemens - have optional feet to convert a flange-mount motor (B5) to a foot-flange (B35). Your local overhaul shop should be able to get them at a nominal cost if you find a flange-mount motor which meets your requirements. Otherwise a decent brand motor is about £350, innominate stuff from China or worse will be about £200.
On top of that you'll need a VFD of around 11kW - 15kW or so, capable of 230V in / 230V out. If you're lucky then you might find a North American VFD with an input designed for 208V 3-phase which will generally accept 230V single phase; I found an A-B 1336 drive on ebay a few years ago which is currently powering the lathe in my garage.
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
They may be able to access the jumpers between coil groups and do a re-connection without a re-wind.
Have you inquired of the manufacturer as to the availability of a 230 Volt machine?
You may be able to exchange the motor at a reasonable cost.
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
I'd advise demounting the grinder part and carefully measuring the motor shaft and flange if any, before ordering another motor.
If you are really lucky, maybe you can find a complete spec for the motor, or at least an exploded view of how it all goes together.
Mike Halloran
Pembroke Pines, FL, USA
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
In IEC-land that C-face with foot is a B35 mounting: B3 indicates a horizontal motor with foot, B5 indicates a horizontal motor with flange.
132 frame is the shaft height in millimetres for a foot-mounted motor. The 'S' suffix indicates a 'short' frame, with others being 'medium' and 'long'. 132S is the standard frame for a 2-pole or 4-pole 5.5kW motor. The standard shaft diameter for a 132S frame is 38mm.
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
One factor that has not been considered is that when you are running your grinder you will be very limited in power available for any other activity, like water heating, air conditioning, and refrigeration.
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Does this work for you?
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Given the datasheet also states full load current of 33A, some service restriction is to be expected. The starter arrangement will need to change too, to support the different single phase starting arrangement.
EDMS Australia
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
No offense, but that could be the beginning (or end) of any number of Irish jokes!
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
How much over 63 Amps will those main breakers handle?
Long enough to start a motor?
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
jraef, you're absolutely spot-on. Over a million and counting. Here's just one example:
An Irishman is struggling to find a parking space.
"Lord," he prayed. "I can't stand this. If you open a space up for me, I swear I'll give up the Guinness and go to mass every Sunday."
Suddenly, the clouds part and the sun shines on an empty parking spot. Without hesitation, the Irishman says: "Never mind, I found one!"
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Unlikely that there will be any winding ends other than those in the terminal box. It won't be built like a US 12-lead motor, I'm pretty sure that winding will be straight 415V.
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
I looked up that mfr's catalog, there is evidence to the fact that although they only show the one voltage on the nameplate, they are wound for Star or Delta configuration and the catalog says they can be 230 or 400V.
http://voltmotor.com.tr/downloads/pdf/en/catalogue...
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
The voltages and frequencies for 2 and 4-pole, three-
phase motors up to 3 kW and 6-pole, three-phase
motors up to 2,2 kW are 230 230VD/400VY 50 Hz.
The voltages and frequencies for 2 and 4-pole, three-
phase motors over 3 kW and 6-pole, three-phase
motors over 2,2 kW are 400 VD/690VY 50 Hz.
VSD compatible motors can be produced upon
customer’s request.
Maybe a transformer AFTER the VFD is a good idea.
Either that or a filter.
Pages 20 and 21 of the catalogue discuss VFD use.
Jeff, will you take a look and give us a valued opinion as to whether or not we need a filter?
What I know about filters can be summed up in two words; "Ask Jeff!" grin
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
At 400V and a motor NOT built for VFD use, I would add a dv/dt filter; it's cheap insurance. But an argument could also be made for using the existing motor for as long as it lasts, then when the insulation fails replace it with the right motor. It's just a coffee grinder for crying out loud, it's not making $10,00/dose pharmaceuticals.
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
An open delta boost with two transformers will give some filtering.
I suggest that we wait until Expat has a motor shop look at the motor.
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Why are you asking Jeff what the price differences are?? I linked the answer to your question showing the prices of both the 400 and 200V options above.
Bill =>
Keith Cress
kcress - http://www.flaminsystems.com
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Also from what I've gathered y'all are suggesting these configuration option from 1st choice and least expensive on to last choice and more expensive?
Oh, and by the way, since I'm talking about expense the digital phase converter which looks like I put house power in one end and 415v/3ph comes out the other end is about £1,800. The rotary phase converter is £1,360. It sounds like your solutions are a lot less £. The main thing it looks like I have to watch out for, since I've only got 60A to put on a circuit, is what the motor wants in amps to start. If that surge is too much I'll be tripping breakers (the digital phase converter, I'm told by the manufacturer, has a 'soft start' so that tripping breakers isn't a problem. And both the rotary and digital phase converter manufacturers now say I can put their gizmos on a 40A circuit). And then once the motor is running it settles down to 10A and we're all happy (and the neighbors too - although not many of them, one across the street and the next one 1/4 mile away).
I digress. So the set up options you think are best, and I'm ranking them in order of expense as they all seem like they will work. Also it seems that as I flesh things out this way the least expense is also the simplest solution. Is that a fair statement? For all these solutions I would put in a dedicated circuit running off its own breaker.
1. If possible convert the motor itself to 230v/3ph: mains ===>> VFD converting 1ph to 3ph power ===>> filter (maybe) ===>> converted motor ===>> coffee is grinding
or
2. Motors are fairly inexpensive so if I can get a 230v/3ph matching motor, buy it and wire it in: Mains ===>> VFD to go from 230v/1ph to 230v/3ph ===>> motor ===>> coffee grinds
or
3. If I have to use the motor the unit comes with: Mains ===>> phase transformer (230v/1ph to 230v/3ph) ===>> VFD ===>> motor ===>> coffee grinds
Would those be the three choices that y'all lean to the most?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
"phase transformer (230v/1ph to 230v/3ph)"
Should be:
"phase transformer (230v/1ph to 230v/1ph)"
Filter:
There is a chart on Page 20 (.pdf page 21) that does not reproduce well.
Link
Use the 690 Volt curve.
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Should be:
230v/1ph to 400V/1ph or 460V/1ph
And I'd skip any filters unless obvious issues appear. Save your money.
So:
4. If I have to use the motor the unit comes with: Mains ===>> phase transformer (230V/1ph to 400/460V/1ph) ===>> VFD to go from 400/460V/1ph to 400V/3ph ===>> motor ===>> coffee grinds
Best bet with the given motor for lowest, nearly non-existant starting shock to your power supply.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
Bill
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"Why not the best?"
Jimmy Carter
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?
RE: Do I need a ROTARY PHASE CONVERTER or a DIGITAL PHASE CONVERTER or an INVERTER?