Inverter or converter for AEW Vicroy milling machine

I am lookng for advice from anybody who has converted a three phase machine to single phase, i am totally out of my comfort zone with electrics and the more reading on the subject the more confused i get. I understand the difference between the two but not which would be the best route for me to go, my AEW vertical miller has all its original wiring intacted and i believe would only need a plug fitting to make it run (in 3 phase mode) with that in mind i think the rotary converter is the simplist option although a much more expensive one. I understand that to use a inverter i need to have the machine rewired, something i cant do due to my lack of knowledge on the subject, but would i need three inverters to run all three motors, if so thats going to be expensive as well. I thought about fitting a 240 volt x axis feed unit and removing the original gearbox this would save the cost of an inverter and the rewiring. I understand theres issues with the Converters reliability or is this just hype!! I am at a loss which way to go so if anybody has advice or experience with this it would be appreciated and help get my Vicroy up and running.

Edited By Ian Richardson 6 on 05/10/2020 16:58:27

Edited By Ian Richardson 6 on 05/10/2020 16:59:07

Ian

If all 3 motors are 380/415v 3 phase you should be able to run them all from 1 rotary inverter rated to the sum of FLC stated on all motor plates.
You may need to have the control circuit wiring/connections checked to ensure the correct voltage is provided for the contactor coils.

Emgee

Edited By Emgee on 05/10/2020 17:28:17

From my limited knowledge I think a rotary inverter would run your machine. I run my 3HP lathe from a Transwave static inverter wired into a 32amp single phase supply. I suggest you speak to one of the many inverter/converter suppliers for their advise. My Bridgeport mill runs from a Chinese VFD but only one motor involved in this.

Just for the avoidance of confusion:-

1. Static converter:- generates a three phase supply from single phase by the use of capacitors to effect a phase shift on the generated phase. Needs adjustment of the capacitance for different loads.
2. Rotary converter:- generates a three phase supply from single phase by the use of capacitors and a rotating electrical machine to provide the generated phase. Usually does not need adjustment to cope with different loads.
3. inverter:- generates a three phase supply by rectifying the input supply to DC and then producing three phases electronically. Does not need adjustment. Can need a filter to stop noise from the supplied motors and interference with radios.

1 and 2 often have a transformer included to get 415V output from the 240V input. 3, by default produces 240V output from 240V input, but one manufacturer modify inverters to add a voltage doubler circuit, so they can produce 415V three phase from 240V single phase.

Rotary inverter:-?????

As Mark points out I mistakenly used the wrong term, it should be "rotary converter", the machine may also run from a static converter but I would prefer the rotary converter.

Emgee

I’m no leccy, but as I see it:

Separate motors, individually controlled by the operator are no great problem for VFD operation. It is the control circuitry, two speed motor controls and the such-like that complicates things, I believe.

The advantage of individual VFDs is that each can be programmed separately. Rewiring the motors to delta, or changing individual, single speed motors to 230V three phase versions is a once-off cost. If dual voltage motors, the change-over is simply made at the motor connection terminals.

The other VFD alternative implementation is that of one large VFD - much larger than the sum of the motors - which will run any, or all, of the motors separately or at the same time. It’s often called a ‘plug and play’ installation. Normally, VFDs sized for individual motors should not be switched between VFD and the motor it drives, but if the VFD is sufficiently over-sized this is not a problem. The motors will only run just as if they were mains driven (no programming or individual protection programs)

The advantage of VFDs is that they waste very little power when not driving the motor(s).

Converters do waste power when switched on and not supplying power (rotary converters run a motor while energised) but can more easily produce the 415 volt output required for the more complex wiring of machines with inter-connected drives.

The choice is yours but clearly depends on the complexity of the machine/wiring. I would say say stay clear of the cheaper static converter suppliers. Take advice from the experts in the field - who will charge more but provide you with a reliable, working system.

If you bought an inverter or as most call them here a VFD. Rated at the full power of all your motors. I am talking 1 inverter to run all. You would have a problem , if you wanted to speed up say your spindle speed then all the motors would change speed at the same time.

Steve.

For advice I can recommend;

**LINK**

Just a very satisfied customer.

Brian

Ian

I have the same AEW Viceroy mill in my workshop.

It is a Brilliant mill.

I have run it from a static converter. The one I used was a really old 5hp model a bit over the top but no harm done. It worked really well. A static converter generates 2 phases, and uses the mill motor to generate the third. You just have to be sure not to wire the control switches to the third phase as they won't work. I did this, but simply just swapped the wires from the converter until it did.

This arrangement worked fine on my mill.

Now I run it from a rotary converter. This is only because I now have a cnc lathe, and it needs proper 3 phases as it does not directly drive a 3 phase motor..

This powers both the mill and the lathe perfectly well and I built it myself.

Hope this helps.

John

Ian

Private messages sent in reply to your message to me.

Emgee

I have mine running off two inverters.

I had to modify the traverse motor from star to delta but was easy enough to do.

I’ll put some pictures up if you like Ian?

where about are you in the uk