I have 3ph/vfd conversions on 2 lathes and a 626 mill…..None of them lack power to turn/mill/drill or cut……

As kwil points out, it may be a setting in your inverter or a faulty motor ( likely/unlikely…the jury is still out in this one…)

Have you tried contacting your supplier and explaining the symptoms to them? If they are reputable then they ought to be able/willing to help….

Three thoughts:

1. Make sure you know how your motor is wired and connected (star or delta configuration?) It does make a difference and the motor may even burn out if it is wrong.

2. If the inverter is correctly set up you should be getting 415v across two phases. You can check this with a meter

3. If you are unsure, please get a competent electrician to assist – 415v will kill whereas 230v usually doesnt!

I upgraded one of my lathes to a 3-phase motor with inverter drive, and I am very satisfied. I had to re-connect the wires from Star to Delta and enter motor specifications into the inverter drive (after reading the manual a few times). So my motor and single phase in, inverter was purchased as a package, but the motor was not wired for Delta and the motor specification was not programmed into the inverter, you are supposed to do that yourself. I hope you get it sorted, good luck,

Thor

Edited By Thor on 30/07/2018 15:57:20

I fitted a Bosch VFD and Brooks .37kw motor to my ML7 and wished I had done it years ago.
I did however wire it all up on the bench to see how it all worked as there are so many parameters which can be changed – it came with 2 books and at first it quite mind blowing!
I’m sure your solution will be a simple wiring change.

Alan

To answer the basic question – no!

Brushless motors and VFD 3-phase motors are great.

Neil

You need to remove the three links connected in series first.

Then, place them as per the left image on the lid, I2 connects to W1, etc….

The links will appear side by side if you wire it correctly.

This will remedy your lathe's poor performance….

If the motor runs in the correct direction, dont swap the incoming wires…

Edited By John Rudd on 30/07/2018 17:03:11

I expect it is safer, for the motor manufacturer, to supply the motor wired star. If the motor were wired delta and someone (a non-electrician) connected it to a 415V three phase supply, the motor would likely be toast. As it is, the motor power would apparently be reduced to about 320W. If running at 25Hz (the 50% you mention?) it could be down to only 180W, so not surprising the lathe did not function properly.

1. You aren't going to burn anything out if you miswire it. Once you reconnect it in delta it should be fine. Just make certain you have set the maximum phase current to whatever it says on the nameplate and check if it's 2 pole (2900rpm) or 4 pole (1450rpm etc). You should get that right in the config too if you want to fix the issue. It would still work fine if you configure the wrong number of poles but if your display is in RPM rather than Hz, it will display speed incorrectly.

2. Wrong – you should see 230V phase to phase unless it's a special VFD that boosts the voltage internally (I think we have been told otherwise).

3. Not sure I'd go with that. 120V may be a lot safer than 230V but I wouldn't argue the toss between and 230V and 415V. I've had 415V across both hands and am still here to tell the tale but it could very easily have been curtains. I CAN tell you that it actually hurt like hell and I haven't done it again since.

Murray

Edited By Muzzer on 30/07/2018 18:10:31

After setting the motor to the lower voltage option, get the hand book that came with it, and check the current settings, for your motor. From the motor data plate. The drive will generally go from 20hz to 50hz, but is programmable to 400 hz. Don't go over 70hz on the max limit. Some say don't go over 60z,(USA and Canada power frequency). Like others have said, as the frequency drops,so does the RPM, and so does the total power available. Also there is breaking options, and slow down/ decelleration settings. I think mine is like 0.3seconds or something like that, and have the accelleration at the same rate, on the motor start up and shut down.

I am surprised that if you brought the unit as a complete set up ready to run, that they would have the motor not in the correct configuration. I am assuming that your VFD is the 220V 3phase output one, and Not the 415V output one.

I have a microswitch inline on the S1 control circuit. This micro switch I use is a normal closed one, and is opened/broken circuit when the contact is made. It stops the lathe for when I do forward thread cutting. And allows me to turn the switch to reverse to wind back for another threading pass. Really good for internal threads. I have some pictures in my Album with it.

Neil

A few years ago one of my friends bought an inverter and was in my opinion was messed about for nearly two weeks before the programming was sorted. When I got involved ( and by the way I'm no expert here) I was told phone after 7 O'clock, then to be told we don't want evening calls, day time only. When my friend call during the day he was told we are too busy to answer queries during the day as we are busy packing parcel and have no time for gossiping. Eventually I got the lathe working, a minor error, but not the back up as the advert said., just sales. Since then I've recommended Chinese made inverters to my friends and all are very happy, especially at the price. John