WJ200-22sf hesitates when starting

[tryan]

I have installed a Hitachi WJ200-22SF on my 3hp Wilton BP clone following the excellent advice I have found in these forums. Everything seems to work properly with one exception. When the mill starts, it does not spin up smoothly. Instead, it hesitates or jerks before coming up to speed. This occurs in the first half second of startup. I have the startup time set to 1 second, but making that longer doesn't change the initial hesitation. Once running, it is smooth and stopping with e-braking and a resistor the motor stops in 0.75 seconds without overload.

There is a troubleshooting reference in the manual "Motor generates an impact at start" that suggests reducing the motor constant J (H024) and/or the speed response factor (H005). I have adjusted both values down but I don't notice difference in operation.

This is probably something that I can live with, but I am hoping someone here might have a solution.

Any thoughts would be appreciated.

 

[mksj]

So a few things you can try:
First is acceleration time I would try F002 = 3.0 seconds, sometimes too fast or slow you will get cogging.
Second try setting the acceleration curve to linear A097 = 00 = linear) vs the default 01 which is S curve which may start out too slow and also cause cogging. Alternative if linear does not work than try adjust the S curve at the start of acceration A151

It is also that you have have the correct motor parameters set.
H003 07 = 2.2 kW motor (3 Hp) if you have a smaller motor than you need to change this setting
H004 01 = 4P motor poles would be for a 1750 RPM motor

Make sure the other motor parameters are correct for base frequency motor and line voltage, etc.

Before you do the acceleration parameters, you need to run the auto-tuning on the motor, ideally with the belt off or in neutral drive position. (you can do a static autotune if you cannot disengage the drive)
Auto-tuning
Set H001 parameter to 002 and hit the run command, from keypad if you have no remote panel, if remote panel hit forward. The motor will hum and then cycle up to 75% of speed twice. When completed the display will show _ _ _ o. set the VFD run to stop and then press the reset key on the VFD.
Go into the programming mode and set H002 = 02 and save, this will load the motor auto tuning data and should make the motor run smoother.

Start with the above and if you still have a problem maybe do a short video of the motor startup and I might suggest other parameters. Some motors - VFD combinations just seem to have problems, most can be worked out.

 

[tryan]

So a few things you can try:
First is acceleration time I would try F002 = 3.0 seconds, sometimes too fast or slow you will get cogging.
Second try setting the acceleration curve to linear A097 = 00 = linear) vs the default 01 which is S curve which may start out too slow and also cause cogging. Alternative if linear does not work than try adjust the S curve at the start of acceration A151

It is also that you have have the correct motor parameters set.
H003 07 = 2.2 kW motor (3 Hp) if you have a smaller motor than you need to change this setting
H004 01 = 4P motor poles would be for a 1750 RPM motor

Make sure the other motor parameters are correct for base frequency motor and line voltage, etc.

Before you do the acceleration parameters, you need to run the auto-tuning on the motor, ideally with the belt off or in neutral drive position. (you can do a static autotune if you cannot disengage the drive)
Auto-tuning
Set H001 parameter to 002 and hit the run command, from keypad if you have no remote panel, if remote panel hit forward. The motor will hum and then cycle up to 75% of speed twice. When completed the display will show _ _ _ o. set the VFD run to stop and then press the reset key on the VFD.
Go into the programming mode and set H002 = 02 and save, this will load the motor auto tuning data and should make the motor run smoother.

Start with the above and if you still have a problem maybe do a short video of the motor startup and I might suggest other parameters. Some motors - VFD combinations just seem to have problems, most can be worked out.

Thanks for this. I had run the auto-tune function previously, but I didn't realize you need to save the results with H002. I re-ran the auto-tune and that cleaned up the jumpy start and made the overall drive much quieter. It now starts smoothly with 1 second acceleration and stops on a dime in 0.75 seconds.

Once again, thanks for the quick response.