ACS800 - Motor Reverses briefly when starting

[sbaum]

Our customer has an issue with an ACS800 drive and 150Hp Motor on a hammermill that I need to resolve. The system has been installed for several years, and on the weekend the motor failed. One of our guys helped to replace the motor, and noticed that when starting the drive, the motor will ramp foward for roughly 2 sec then reverse for the same time, then jump forward to where it should be in the ramp. Ramp time for the system is around 4 minutes.
This problem has only started after the new motor was installed, and no parameters were changed (that I am aware of) on the drive.

I remember seeing this happen on a ACS350 with a 1hp motor several years ago, but I wasn't the one to correct it a can't remember what was done.

FYI this isn't exactly a graceful way to start a 150hp Hammermill...

 

[iant]

Sounds like a Delta connection issue.
I understand it is a Drive - but if the motor coils
U-U1
V-V1
W-W1
are incorrectly wired you may be seeing the same effect as the old growling in the star delta starting system
eg. U-U1, V1-V, W-W1

 

[sbaum]

Thanks. I was thinking it may be a connection issue as well.

But I needed the second opinion before I blame that,
because the guy who made the motor connections signs my paycheque

 

[DickDV]

Doesn't hurt to check the connections but, if you installed a different motor and did not redo the motor ID run at 9910, you are lucky the motor runs at all.

Disconnect the motor from the load and change to Local mode on the keypad. Go to Parameter 9910, select Standard, and press the start button on the keypad. The drive will energize the motor for a few seconds and then spin the motor up to 80% of max speed, change the motor speed a couple of times, and then stop. ID Done will display on the keypad.

You will then have a proper motor model again and your application should run like it did before the motor changeout.

 

[sbaum]

I am planning to do the ID run tomorrow as I can't verify it was done when the motor was changed.

However, the drive will to an ID Mag on first start after changing a motor. Isn't that sufficient to get the motor running?

I am under the impression the ID run creates a 'better model' for tighter vector control of the motor.

 

[DickDV]

I've found that the drive will only do an ID Magn when there is no motor model in memory. If it already has one (the old motor) and it doesn't match the new motor, bad things happen.

 

[sbaum]

Performed a standard ID Run on the motor today.

Problem solved.