3 Phase invertors for a Myford ML7

Hello Everyone,

This is my first post on the Forum. I have had an ML7 in strage for nigh on 20 years. It had been overhauled by Myford, before storage. it came with a 3 phase Crompton-Parkinson motor. Right now I am on single phase so an invertor is required. I would want something with a soft start capability and maybe a flux type circuit to maintain torque, but the latter is not essential.

There appears to be a plethora of units on the market, so the choice comes down to reliability (and maybe a bargain, although this is usually not had with a reliable unit!). So what have been members experience with various units. Transwave appeared to have some cheapies, but then realised they were Chinese! Not my favourite manufacturing country!

Regards,

Andrew.

Hi Andrew,

I've fitted Mitutoyo S500 inverters to my mill, bench drill, and the lathes and mills of various friends. They have all proved very reliable and I can recommend them. I've fitted the E500 unit to my lathe 'cos its 2HP motor was too big for an S500.

Regards, Gary

Hello Gary,

Thanks for the info about Mitutoyo Drives. Any chance you can tell me of any suppliers? A Google search turned up lots on dial gauges and calipers, but nothing on Mitutoyo 3 phase drives!

Regards,

Andrew.

Most of the branded names are just as good as one another, most are made in japan or Taiwan regardless of who makes them. Fuji make a lot that are branded in other manes like IMO and Smartdrive.

Not as prevalent nowadays but do check that whatever you buy comes with the programming panel.

Mitutoyo and ABB were buggers for this in the past, sell a cheap inverter and then the panel was extra, need to run at above 60 Hz Sir ? that's £xxx.xx for an add on panel.

Last problem are the manuals.

Inverter manufacturers have an unlisted competition to write the most obscure manual and points are awards to the manufacturer who can write the most hair tearing manual.

Sounds funny but it isn't.

Local company to me rang up and said they had a new Siemens inverter 15Kw and could I help them out programming it?

All they wanted was for the motor and inverter, in a big screened box to go on this machine and 20 foot away they wanted a remote pendant with push button start / stop controls, what's know as 3 wire system.

Their electrician couldn't sort it as I had had a fair bit of inverter knowledge could I sort it ?

Inverter comes down with the manual which and I'm not joking was A4 and 512 pages.

Quick look thru and it didn't stand out so did a search, found the manual on line so i could be a keyword search for 3 wire / remote / pendant / rhubarb etc, no joy.

So as not to waste time rang Siemens technical in London, they promised to get back to me.

Promised 3 times that afternoon - no luck.

rang them the following day and they said they would get back to me later.

two hours later Germany rang up wanting to know what the problem was, explained it all again and they said they would get back to me.

In all fairness they did and said change this parameter to this, that to that etc and in all fairness when I did it it worked.

I asked Germany why it was so difficult to follow these manuals and why could they no do a simple wiring diagram for 2 wire [ relay type ] and 3 wire push button.

Their reply was "No one wire 3 wire today " ? ???

Once I knew what the settings were i went back to the manual and nothing in there would have given me a clue that it was these parameters that I needed.

It goes without saying they won that years prize

I have a Mitsubishi and an ABB. Both have reasonable manuals but, surprisingly I found the Mitsubishi the easiest to set up with remote controls.

Russell.

Andrew, If it's any help, I have a Eurotherm 650 drive on my Warco GH750 lathe and it's been trouble free since new, about 12 years ago now [Eurotherm are now made by Parker SSD] My Chester LUX mill uses a WEG drive, again, trouble free . My other lathe a DSG uses a specially built drive so would be of no interest to you.

Regards,

Raymond.

I have used an IMO inverter to control a 1/2 3 phase motor I have fitted to drive my Myford VMD milling attachment via a toothed belt.

Programming of the controller is easily carried out on the unit itself by going into one of the setting modes.

A truely mass of parameters are accessible, I have the frequency output set to allow 0Hz to 75Hz leaving the rest at the default settings.

Works a treat, highly recommended!

Alan

Hi

I fitted a Imo inverter and a 1/2 hp 3 phase motor with a control pod to my Warco WMT300 lathe last December. Very easy to fit. Instructions easy to follow. I am very pleased with it There are some photos in my album. Would recommbmend it.Got it from Transwave (just a happy customer)

John

Edited By John Thorne on 22/09/2012 21:40:22

Edited By John Thorne on 22/09/2012 21:41:42

Edited By John Thorne on 22/09/2012 21:43:34

I apologise for any confusion - I had a really senior moment when I wrote this - I meant MItsubishi, NOT Mitutoyo. By the way, the Mitsubishi S500 units have the parameter pad built in. I've added some photos that show the two S500s mounted under the lip of the swarf tray of my Centec mill, tilted upwards so they can be easily read by glancing down. The remote controls are attached to the end of the table.

I agree with John about the quality of the manuals though. I wired my first S500 up on the bench - it was the first time I'd ever seen an inverter. I could easily control the direction and speed of the motor from the built-in pad, but when I added a remote external switch and potentiometer as shown in the User Manual it was totally inoperative.

Several calls to Mitsubishi agents resulted in advising me to check the parameters again, although one said to send them my settings and they would sort it, which I did - I heard nothing more.

I downloaded another (thicker) manual from the net and read it carefully. It turned out that the 55 page "Basic" manual supplied in the box was written for the American and Asian market, and the unit was wired accordingly. The 181 page "Detailed" manual showed that a little jumper plug controlled the wiring - one way was for America, the other way for Europe. I swapped the jumper over and the external controls worked.

Although the manual included in the box went into such details as specifying the size of the screwdriver needed for the terminals, it said nothing about the significance of jumper plug.

Despite this, they are good inverters.

Gary

Edited By Gary Wooding on 23/09/2012 09:28:13

tHi there,

I use an old siemens inverter (pre micromaster series) on my ML7 and it works great - parameter programming was easy with the downloaded manual. I also have a couple of other inverter driven machines, and the only trouble I ever encounter is running more than machine at a time. The earth leakage from inverters can be as much as 20mA, and with modern domestic electronic devices (washing machine controls for example) on top of the 20mA leakage from an inverter, or even two inverters can trip the RCD in the house dis board. A split load wiring system would allow you to run the inverter off the non-RCD protected circuit and not encounter too many problems with these small earth leakages.

Neil.

I've got a Teco 1hp bought from Drives Direct via ebay driving a new TEC 3 phase motor on my Barker lathe, an Omron V1000 (ebay) driving a new Marelli 0.5hp on my Chester Champion, and a Mitsubishi E700 (ebay) driving the original Hoover motor on my Elliott shaper

All easy to set up as they came with manuals (sometimes on a CD). All with soft start and slow down, jog and ability to drive above 50hz. The lathe and mill ones have remote control stations with potentiometer speed controls for variable speeds which I would recommend as you don' have to reach for the inverter to set the speed

Andrew you dont have to use an inverter there are other ways of powering 3 Phase equipment from single phase.

Paul

Thanks for the response so far!

It looks as though there is not a lot between the units in the reliability stakes. However I suspect that is because the model engineer doesn't use his kit as much as professionals!

Paul I do realise that there are other ways to run 3 phase equipement from single phase. I gave up on rotary convertors many years ago and the lead/ lag. capacitor, inductance arrangement is a dog's dinner. I am glad to hear that you get away with such setups. I think they are not very smart. Mind you I have a very large lathe that takes more than 3kw and I am stuck with the old fashioned bodges for this one.

Regards,

Andrew.

Andrew - perhaps not technically helpful, but I have an ML7 (Trileva) and recently replaced the knackered single phase with a new 3 phase. Control provided by a secondhand Omron V7 inverter/controller. This was all connected, ready to go and just left me to (cautiously!!) rewire from delta to star (?) and plug it in. Result? ... superb! Soft start, easy speed control in any of the three belt selections (plus 3 backgear, if needed) - almost makes the clutch redundant. Highly recommended.

Rgds

Bill