Motor won't run right with VFD in sensorless vector mode

Motor-Dual voltage 230/460 3HP Dayton "Watt-trimmer" 3 phase motor.
Drive-Hitachi WJ-200 2KW VFD.

Previously was running a Baldor 1HP motor with the drive. Ran great. Needed more power, so tried putting the used Dayton motor on the machine. Changed the parameters on the drive in regards to the amps of the motor. In sensorless vector mode, the Dayton motor is very jerky in trying to start. The spindle on the machine turns easily. Take the belt off, and the motor seems to have a slight hesitation, but it starts and runs without a problem. Put the drive in constant torque mode, the drive starts the motor connected to the spindle without a problem, but the Dayton motor sure doesn't seem to have any power-its worse than the 1HP Baldor.

I put another motor I had on the machine-a 1.5 HP motor. Runs great in sensorless vector mode and has good power.

Is there such a thing as a motor that is not compatible with a VFD? Or is my motor bad? It came in a lot of stuff I got, and I'm not sure about the history behind it.

Thanks!

Maybe it is bad...

Run the self tune operation when you change your motor.

rons said:

Maybe it is bad...

Run the self tune operation when you change your motor.

Click to expand...

+1

My motor absolutely had to have the drive tune itself for sensorless vector to work.

I also ran the tune program once it was installed in the lathe, to good effect.

Did you set the basic motor parameters (Voltage, current, frequency)? Usually those are separate from any tuning, the VFD does not know the motor limits just from measurements.

Also, which exact model is the VFD?

The problems mentioned are not unusual for a VFD which is either too low power, or is set to current limit too low, as might be expected if the previous motor was smaller, which you indicate is the case.

Sensorless vector control absolutely MUST be tuned to each individual motor. When you change the motor and don’t re-tune the drive, the drive is trying to operate the old motor and is not seeing the correct response.

Sorry, I had the specs on the drive wrong, its actually a 1.5KW WJ200-015LF

Yes, went through and changed the basic parameters that were different between the motors, amps/volts.

That is really interesting that the drive needs to be tuned to the specific motor. I'm almost certain I didn't do that, as I don't remember the procedure for doing so! I've ran a total of 3 motors with this drive without tuning. But they were all smaller-1.5HP and smaller. Maybe with the 3HP being near the capacity of the drive, it must be tuned for it to even run?

Thanks for the input, appreciate it!

The WJ200-015SF is only rated to 2Hp in constant torque which you should be using, so very simply it will falter with a 3 Hp motor because it is exceeding the rated current for the VFD. So you either need to run a 2 Hp motor or upgrade to the WJ200-022SF.

VFD's load motor constants (Hitachi Standard) or what they consider is general parameters. Some motors run well as such, others will not and be somewhat rough and coggy, often under acceleration. I have not encountered a working motor that did not work with the WJ200, although I could not get a dual speed motor to work well (rough) and it had to be replaced. Auto tune only needs to be run once for a particular motors, the parameters are loaded into memory, but you need to specify in the motor parameter setting to use the auto-tune parameters H002 = 02 as opposed to the Hitachi standard H002 = 00. Auto-tune if run with motion H001, then the motor must not be attached or turning a drive system, so the drive belt/coupler must be removed from the motor.

I have encountered other VFD/motor combinations that just didn't work, typically under acceleration. Often this may be it is at the current limits of the VFD, not able to auto-tune the motor or limited available drive tuning parameters. In most cases these are less expensive VFD models. But in your case the issue is the VFD is not rated for your motor size.