VFD and Permanent Magnet Motor


Thread Starter

Bill Code

Is it possible for a VFD (Powerflex 700) to operate with a permanent magnet motor?

The application is a machine tool spindle drive. The motor is a Kollmorgen V2601-CN22 (20 HP, 4500 RPM) controlled by a Galil DMC-1780 controller signaling a Kollmorgen VECTORSTAR VSA28-0012 amplifier. The plan is to replace the VECTORSTAR VSA28-0012 with a PowerFlex 700.

Has anyone done this?

Bill, I hate to be mean, but why in the world would you ever replace any drive with a AB drive? Just cause you haven't enough fun or had enough challanges at work lately? Maybe you want to buy a drive you have to support yourself vs. be able to call somebody to help?

I would suggest calling kollmorgen and seeing what they have to offer, if they offer the Servostar to run this motor, then I can say I have had several of them for years with no failures.

Note no matter what drive you shove in there, you will have to spend time re-tuning this system to work like it used too... retune the Galil and drive loops... If you find a drive to work, you may ask somebody to do this for you who has lot of experience...in tuning.

To answer the question, no I haven't used a 700 like you want to, but I do have a lot of 700S's driving MPL's that I'd like to go away.
The replacement is not my idea. I believe the end user talked to Danaher Motion. The failed
amplifier is no longer in production or supported. I believe (I was not part of the discussion)

Danaher recommended replacing the motor and the amplifier. The user is attempting to re-use
the motor. Hence the plan.

Another wrinkle I just heard is the VFD is 480 VAC.

My part is to add I/O to the controller to send a speed reference to the drive.
Bill, From my experience, most drives that can run a permanent magnent AC motor can run a servo as well. Since, that is effectively what most servos are today, a PMAC motor. So the guy may need a 700S vs. the 700. I would call Rockwell to confirm. However, they may not want to touch it with a 10ft pole.

If you can't confirm it will work, I would have your customer, since this is their choice of drives, to have it started up and the internal loops tuned via the keypad before you buy your plane ticket.

That way you don't waste your time and his money.

And since you are doing only I/O shouldn't that IO already be there from the Galil? +/- 10VDC for speed, enable and fault lines etc.? Is the Galil simply giving a speed command or is there position control loop in the galil? I've done both, one where I needed to position the spindle for threading etc. and straight speed for general machining/grinding.