Phase converter / inverter

[SkelParticipant @skel]

Hi all.

Ok, another question for you guys.

Very impressed with the level of knoweledge on here so far.

Here goes…

In my workshop I have single phase 240v electrics.

I have a bridgeport milling machine with a 1.5hp 3 phase 415 volt motor,

it also has a suds pump motor which is about 1/4 hp 3 phase and 415 volts so this machine does really need 'proper' 3 phase or as near as can be realistically achieved due to the motors being single voltage.

Now, I also need to run my Harrison M300 lathe which happens to have a 3 phase 3hp 230v / 415v dual voltage motor,

it also has a 3 phase 1/4hp suds pump motor which maybee dual voltage but I cant tell as yet.

So the quandry is this.

How do I make em all work reliably without having a phase converter for the mill and an inverter for the lathe with seperate static phase converter for the two suds motors ?

Any ideas or experiences you would like to share would be greatly received.

Cheers.

Skelly.

[SkelParticipant @skel]

Boggled as to how to do this.

[mick70Participant @mick70]

Speak to direct drives 01623720730.

Got converter from them for a dual volage motor to go on my southbend.

Very helpful.

[BazyleParticipant @bazyle]

If you are not after variable speed the big blue Transwave boxes produce 415v three phase not the 240v three phase of digital inverters.

[duncan webster 1Participant @duncanwebster1]

provided you can reconnect the suds pump motors as delta you can run them at fixed speed from 240v single phase using capacitors. See https://www.youtube.com/watch?v=6UcDM3hm0XM

Edited By duncan webster on 25/10/2015 20:24:04

[AjohnwParticipant @ajohnw51620]

I used a Transwave box for a couple of years without any problems providing i set it as they instructed. If I played with the settings more out of curiosity all seemed ok but from time to time things didn't work out so eventually I just set it up as instructed and didn't have any problems at all. One thing I will add to that. When these were popular many would buy a 3hp unit or even bigger as they can be turned down via the knobs. I just went for one that was more than adequate for the motor it needed to run. Transwave will advise you about the suds pump.

Some people set up a motor converter that uses a generator and get 440v 3 phase that way. I know nothing about these.

I think I have read about a method that use capacitors and more than one motor. Might be details on the web.

Sometimes 3 phase 440v is available and close to the house and just not wired so can be installed but I have no idea of the costs. Houses are just wired off one of the phases so a lot depends on how the meter etc was initially installed. In older properties in B'ham I have been told that getting at it is often relatively easy. Good job too if in the future we have to heat our houses entirely via electricity.

John

–

Edited By John W1 on 25/10/2015 20:38:09

[Jim BParticipant @jimb32695]

Hi Jon,

The best solution is getting 3 phase put on. If you're incredibly lucky the transformer on the pole will not only be the right one but also right next door. A friend had it put on for I think it was between £700-£800 pounds last year and he was in the situation I have described.

If the greedy lot at your electric supplier want more and it's silly money ask for a detailed breakdown of the costs and watch the price drop. The second best option is a rotary converter which just puts out what the machine needs unlike a static which can and will kill a suds motor in minutes if you forget to turn it off and you'll only need one rotary converter to run both machines. If it's big enough both machines together.

There can also be issues with statics on some motors where no matter what setting you use it isn't right. They can also heat the motors up because they are not actually kicking out 3 phase. It is two phases and a ghost phase and if you get the control gear on this one nothing will work! I have also had to renew the motor bearings on a machine before now because it had been used for long periods and had got too hot.

I use a rotary converter to demostrate machines working (7.5Kw Transwave) and the machines seem happy enough on it plus it's very quiet. The machines are often louder than it is!

Jim

Edited By Jim B on 25/10/2015 21:08:49

[Ian PParticipant @ianp]

Posted by Jim B on 25/10/2015 21:05:41:

Hi Jon,

I use a rotary converter to demostrate machines working (7.5Kw Transwave) and the machines seem happy enough on it plus it's very quiet. The machines are often louder than it is!

Jim

Edited By Jim B on 25/10/2015 21:08:49

Well that surprised me (machines louder). A lot depends on what machines we're talking about but I would not want anything that had to make a noise converting single to three phase.

It might be acceptable in an industrial, or near industrial environment, but for home workshops say in attached garages I can see it would be a no no.

Ian P

[Mark CParticipant @markc]

Just buy inverters for everything, 2 big jobs for the main motors and a couple of tiddlers for the pumps. Leave the pumps running at 50 cycles (or only have limited speed control so you can vary pumping rate). Fix the main motors so you have variable speed. Bin the standard wiring and change the motors over for delta (if they are fixed 380V you can convert them DIY style, buy a new motor or take them to a re-winder and get it done for you). Job done. If you buy any of the converters they are both expensive (more than 4 cheap inverters) and don't provide any extra benefits – soft start, speed control etc.

Mark

[Bob Brown 1Participant @bobbrown1]

I agree with naughtyboy speak to someone in the know as all it costs is a phone call.

[paul 1950Participant @paul1950]

Posted by duncan webster on 25/10/2015 20:23:43:

provided you can reconnect the suds pump motors as delta you can run them at fixed speed from 240v single phase using capacitors. See https://www.youtube.com/watch?v=6UcDM3hm0XM

Edited By duncan webster on 25/10/2015 20:24:04

that is rubbish it will only work if the motor is vertical and not under load i have tried this and so have other people that i know

[EmgeeParticipant @emgee]

Posted by paul 1950 on 25/10/2015 22:30:16:

Posted by duncan webster on 25/10/2015 20:23:43:

provided you can reconnect the suds pump motors as delta you can run them at fixed speed from 240v single phase using capacitors. See https://www.youtube.com/watch?v=6UcDM3hm0XM

Edited By duncan webster on 25/10/2015 20:24:04

that is rubbish it will only work if the motor is vertical and not under load i have tried this and so have other people that i know

Not complete rubbish, my Bantam suds pump has been running when needed for the past 15 years with such a connection.

Emgee

[AjohnwParticipant @ajohnw51620]

Noise out of Transwave 240 to 440 3 phase passive converter ?????????????? Set incorrectly and the motor stalls and there will be some noise.

Noise out a motor driven by an inverter – yes. They tend to be noisier than driven via 3 phase due to the switching frequency used to drive them.

John

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[Ian PParticipant @ianp]

Posted by paul 1950 on 25/10/2015 22:30:16:

Posted by duncan webster on 25/10/2015 20:23:43:

provided you can reconnect the suds pump motors as delta you can run them at fixed speed from 240v single phase using capacitors. See https://www.youtube.com/watch?v=6UcDM3hm0XM

Edited By duncan webster on 25/10/2015 20:24:04

that is rubbish it will only work if the motor is vertical and not under load i have tried this and so have other people that i know

Thats a strange conception of the word 'rubbish'

There are thousands of motors running far more powerful motors than suds pumps, but like the Bee they just keep in working.

I know of one milling machine that the manufacturer supplied as single or three phase and both use the same motor. Only difference is the single phase machine has a capacitor (and a bit less power).

Ian P

[Mark CParticipant @markc]

The only time you can hear an inverter is when it is labouring at very low speed, by then you will be concentrating too much on the job that needs to go that slow so you are unlikely to notice that even.

You have at least two of your motors can run on an inverter (lathe), the BP may be marked as single voltage but have a look inside the cover in case the star point is visible. If not, worse case is a new motor for the mill…. Still much cheaper than all other options and boat load of extras to boot. Digging out the star point to convert for 240 volts is not as onerous as it sounds search star point on here (or internet even).

Mark.

[Richard Clark 1Participant @richardclark1]

Hi Jon,

I had the same problem when I purchased my Bridgeport mill, I read lots of things about inverters and static converters changing motors etc and how you need to switch in different capacitors when its under load etc, all of which I did not want to do.

I used to work at a company that made switchmode power supplies and I did not want any of the problems of switchmode electronics driving motors ( been there seen all that pops and bangs and smoke).

I purchased a Transwave Rotary converter and it gives the nearest thing to 3 phase output and it is very reliable its the 3HP version (2.2kw) and you can switch on any thing you desire suds pump power feed to X and Y table all of which is the original fitted Bridgeport equipment.

I then purchased a Colchester lathe 3Hp and then all I do is just plug that in to the Transwave Rotary and it works just as it should no rewiring just plug in and use as the makers intended.

I have seen people fit 1phase 240v motors into Colchester lathes but the machine is pretty much underpowered and worthless in my opinion.

If I were you I would look at getting a Transwave Rotary it uses a real motor to generate the 3rd phase and is a superb piece of kit not the cheapest solution but if you dont want digital converters on everything and worry if you have to switch the suds pump on after the main motor etc then go for the Rotary its the closest thing to having your own 3 phase generator running.

Digital converters are cheaper (but you will need one for every piece of equipment) but they use electronics to create a simulated waveform generated by an oscillator and then a power o/p stage and all this electronics can be upset by spikes on the line or just pop and blow a fuse leaving you to either send it back to the makers for repair(costly) or purchase a new one (costly) or opening it up in hope that you will find something that now looks like a black burnt mess on the pcb.

I also have a seig X2 minimill it has a DC switchmode power supply it went pop blew a fuse took out a potientiometer (speed control knob) and then had to put some new components into it not easy when the original part is no longer made and then you have to look up transistor equivilents etc.

so having worked in the electronics industry makes me more inclined to stay away from it for the purpose of powering up motors.

Well thats my thoughts hope it helps Jon

Regards

Richard..

[MuzzerParticipant @muzzer]

Posted by Richard Clark 1 on 26/10/2015 20:21:40:

I used to work at a company that made switchmode power supplies and I did not want any of the problems of switchmode electronics driving motors ( been there seen all that pops and bangs and smoke)….

Digital converters are cheaper (but you will need one for every piece of equipment) but they use electronics to create a simulated waveform generated by an oscillator and then a power o/p stage and all this electronics can be upset by spikes on the line or just pop and blow a fuse leaving you to either send it back to the makers for repair(costly) or purchase a new one (costly) or opening it up in hope that you will find something that now looks like a black burnt mess on the pcb.

….so having worked in the electronics industry makes me more inclined to stay away from it for the purpose of powering up motors.

Dear god, what a philistine. If you plan to stay away from switchmode power electronics, you will need to avoid CFLs, LED lighting, all televisions, modern boilers (variable speed fans and pumps?), almost all vehicles (power steering? engine management? hybrid vehicles?), aircon (blah blah), most white goods, most modern machine tools etc etc. The list is almost endless. The reliability of these products is generally pretty damned good.

Good luck huddling around your candle at the back of your cave! You were either a really crap engineer or simply worked in the building.

Merry

[Steve PaveyParticipant @stevepavey65865]

I had loads of help from forum members on this topic. See **LINK**

I have yet to sort out the coolant pump, but I think I will probably have a go at adding a capacitor or two to get it to run on single phase (do a search or a Youtube video by John Mills 'Doubleboost' as he used this method for his coolant pump).

[Chris GunnParticipant @chrisgunn36534]

I have been running my 3ph Bantam with suds pump from a Transwave converter for 25 years or so, no problem, switch the main motor on first, and the suds pump second, and switch them off in the same order. When I added my 3ph Bridgeport 10 years ago, I did the same, and again, switch the main motor on first, then suds and or the feed motor second, and in reverse order when finished. All the existing motors, and switchgear can be used without any alteration at all, a big bonus surely.

Chris Gunn

[KWILParticipant @kwil]

I run my Bridgeport and Harrison M300 with theri own dedicated Inverters. I also run the suds (rarely used as I cut dry a lot of the time) on the same inverter provided 3 phase, the load is so small it does not have any downside effects.

[SkelParticipant @skel]

Hi..

Thanks for all the replys folks.

I had no idea there was so much passion for this subject..

I have came to a few conclusions.

A static (capacitor type) phase converter is a no no because they have a minimum output which is excess of my suds pump.

so if I run my suds pump on its own it may overheat.

Getting 415V three phase wired in to my workshop is also a no.

That leaves me with 2 options.

A rotary converter or an inverter.

I think because of the degree of control an inverter gives you, I'm going to go down this route.

I will also be swapping or modding the BP motor and running that from an inverter also.

Now all I need is to find a good inverter that has the following functions..

Braking.

Programable accel.

Ability to run with machine E stops and contactors.

Speed and jog control (remote)

Any ideas or experience would be greatly received.

Cheers once again for all your comments, it has helped me very much so far.

Skel.

[Mark CParticipant @markc]

Jon, that list is pretty much standard on all drives these days. Steve Pavey can help along with plenty of others but I think his conversion was the first time he has done one and his was not the easiest as he went the DIY motor conversion route.

Mark

[Clive FosterParticipant @clivefoster55965]

Having done the static converter, rotary converter, individual machine inverter and currently Drives Direct Plug'n Play whole shop inverter with smoothing coils on the output I can reasonably claim some relevant experience. If the electrician finally gets off his tail I should have utility 3 phase hooked up by Christmas, more like £5,000 than £500 to install plus trenching & groundworks tho'. Guess that will be a full set.

Static capacitor type converters at one per motor work pretty well when tuned in but over 1 1/2 hp can be problematic. I've built several but a proper, safe, plug'n play design with built in NVR and automatic switching out of the start boost capacitor is too expensive these days and often a bit touchy to tune. So you need a stock of capacitors. Done right its very effective. Only one I'd still do was a system like the one I fitted to my old Pollard Corona drill. Run cap permanently on the motor. Pollard built start button with monster contacts handles the start boost capacitor just fine. Hold the button down for a one-two count and up to speed.

Motorrun brand static converter with step up transformer worked OK to run the Bridgeport but needed capacitor switching according to load and always buzzed. Could have handled more machines if I had them but switching would have been a pain. Converting to a rotary version with a 5 HP motor on the back killed the switch fiddling but buzz was much worse. Especially after I put it on a shelf and set the whole shop going! Friend Mike has a Transwave set-up for his shop which is a building in a building type inside a steel panelled barn. Transwave lives in the barn 'cos its too noisy in the shop. Not noisy noisy but more than irritating. Had some issues with starters due to poor voltage regulation on start-up. Motor dragging the generated phase down but we eventually sorted that.

Single inverter per machine works as it says on the tin but costs do add up when you get more kit. I'm up to twelve three phase machines now. The shaper is still on its own inverter. Although the Eillot 10M has a good range of gearbox speeds I like the extra control and low speed start up.

10 HP plug'n play inverter from Drives Direct just works like utility power should. Zero futzing about although I'd always advocate the output smoothing coils even though it adds around 50% to the price. Unless you are certain you only need one or two machines thats the way I'd go despite the higher cost over one or two individual inverters. Much to be said for do it once do it right. I shudder to think of how much time I've spent over the years fiddling to get stuff going. Admittedly in days of yore fiddling and affordability went hand in hand. Building static converters for other folk and a bit of astute (OK lucky) trading means I'm not unreasonably out of pocket all told.

Clive.

[Steve PaveyParticipant @stevepavey65865]

Mark is right – this was a first for me – although I have taken a few single phase motors apart to replace bearings and so on I haven't dug into the windings before. So I can offer the perspective of a first timer so to speak.

If your motor plate says 380v rather than 380/220 you'll have to take the end plate off the motor and locate the star point – I posted a couple of photos on the other thread, as did one of my 'advisors'. Looking back it wasn't particularly difficult and I would certainly tackle the same job again.

I think most inverters are capable of the functions you list – whether you need braking or not I don't know, but my Harrison has a mechanical clutch/brake so I didn't need the inverter to do this for me. I bought a Huanyang from an eBay seller called technical.jrs – apparently there are Huanyang copies around which are to be avoided. I did consider a known brand like Hitachi, Mitsubishi etc but they are considerably more expensive and I wasn't certain my motor conversion was going to be successful – given that uncertainty my dubious logic pointed me to a £90 solution rather than spend £250-300.

I also bought some shielded cable, decent push button switches, heat shrink sleeving and proper cable glands so I could make an attempt at some decent, safe wiring. Also I used a 240v DOL starter on the input side of the VFD to isolate it from the 16a supply (for some reason the manual says you mustn't do this and I can't see why – how would the VFD know whether the contacts are being closed by an electromagnet rather than a fleshy digit?).

Setting up the inverter is not easy because the manual is so confusing, but there are loads of forum posts around (this and other forums). I just set the motor up first (speed, amps, no of poles etc), and left all the external switching until I was a bit more conversant with the setup procedure. I got there with the help of several others who posted there setup parameters for me to work from. Be aware that many inverters are used with cnc spindles, and need very different parameters to the induction motors on a lathe or mill, so don't blindly copy the first list of parameters you come across.

Was it all worth it? Absolutely. I now have a little experience of a topic I'd only read about before, I'd happily do another one tomorrow and I also have a clear picture of my lathe's electrical system should I need to delve into it in the future. I've run the lathe for a few hours over the past week with no problems whatsoever.

[SkelParticipant @skel]

Cheers guys.

Yes the motor plate says

240V 3 phase delta

414V 3 phase star

So no problem there.

Apparently all the M300/250 machines have this dual voltage motor.

Also, I have been told that there is an inverter available that can run the motor unloaded (belts off) and it will figure out its own running parameters on its own.

This sounds good to me. if only I could remember who told me..

I am also looking at the ones that Transwave sell, IMO Jaguar Cub.

They have a remote pod and the people there seem very helpfull and even call me back when they say they will,

which is something I like very much.

The bloke at Drives Direct seems helpfull also.

I dont mind spending a few hundred quid to get the job done right, first time.

A guy at work says that the ABB ones are best as they are very easy to program.

Lots of research to do..

Skel..

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