PM1440GT Motor Swap...

When this kind of cogging problem has happened to me in the past, it was incorrect motor parameters. Maybe change your max speed setting from 90hz to 60hz and see if that does anything. I wouldn’t think that should cause it, but maybe the latest firmware is calculating the V/f ratio based off of 90 and not 60 like it should. If that is the cause, might explain why auto tune is not working.

Since the problem got better by changing the S curve, it sounds like the auto torque boost might not be working correctly. Parameter A041 is set to auto in the parameters you posted, switching that to off might work too.
 
The base speed is set to 60 Hz, these motors are rated to 2-3X their base speed (5-6K RPM with full Hp). I run these motors all the time, and have not encountered any cogging. The whine you hear with Auto-Tune is specific to that testing procedure, it has nothing to do with regular operation, and these inverter vector motors are designed to operate at the higher carrier frequencies. A vector motor can only be run off of a VFD, and requires the VFD to detect the motor parameters. As I mentioned these motors are quite a bit different then the Hitachi Standard, one reason where the Auto-Tune is important and then making sure that the VFD is running off of the new parameters. Every VFD manufacturer is different in this regard, and I have had cases where the VFD-Motor just wouldn't work together. I have not seen this with the Marathon, Baldor, Lincoln inverter/vector motors and the VFD's that I have used from Hitachi, Yaskawa, Teco and Automation Direct.

If it works as currently configured, then leave it alone and move on.
 
Breaking news: Auto-Tune works.

I talked to tech support at drives warehouse, again, awesome guys.


He recommended playing with the base and max frequencies. He said to try 60/60 or something higher than 60 for base. I set it to 75hz base, 90 max. The tune ran fine.


He also said to double check B022 (Overload restriction level) but I do not understand what the numbers are for this.
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The motor seems to want a little longer acceleration time (4.5s) than I'd like, but I'm OK with it. This is with the motor constants set from the auto tune, sensor-less vector, and a belt that sounds like someone in latex pants rolling around in a shower curtain. :D
 
B022 is the % motor overload for up to 1 minute. If accessed through the Hitachi WJ200 software it shows up as %, if accessed through the keypad it shows up as amps. So you take the motor name plate FLA x % = overload amps. Default is 150%, which is what is use for stock newer motors, inverter/vector rated I use 170 or 180% which can give you higher torque for low speed cutting that isn't prolonged. Older motors I usually set this at 120% along with lower carrier frequency and a few other parameters to be gentler on the motor. Many VFD's cannot go to 200%, and it can cause motor over heating on fan cooled motors, TENV are designed to work down to almost 0 speed. Getting the motor base speed and poles is important, essentially by raising the base speed it is changing the V/Hz pattern at what motor speed the volts peak at, after which the Hz continues to rise but the voltage remains the same. In constant torque not in SV mode you can dial in different V/Hz curves which can help starting heavier loads. There are also some set points along the V/Hz curve depending on the VFD manufacture. If I was sitting in front of your machine/VFD I could probably dial it in for you, but usually the VFD in SV with automatic torque boost should take care of this.
 
>If accessed through the Hitachi WJ200 software it shows up as %, if accessed through the keypad it shows up as amps
Ah! That's where I was confused...


I'll have new belts tonight and will run it for a while.
 
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