Ac motor get stuck when changing direction

[assaf]

Hi everybody,
I am building a motion driving simulator.
it has six ac motors (400v 2 pole 3 phase 750w)
and six vfd’s (telemecanique altivar 16 750w)
i bought a controller that someone builds for simulators that connects to the pc and control the six vfd’s.
this controller send speed and direction commands to the vfd’s (by changing voltage)
every vfd is connected to a resistor that acts as a brake.

only one of the motors get stuck sometimes when changing the direction of rotation.
when it gets stuck the vfd shows its output current is about 1A.
sometimes it get unstuck after a few seconds. sometimes not.

when i disconnect the GND between the controller and vfd and reconnect it gets unstuck.
also if i press and release the STOP button on the controller board it gets unstuck

tried connecting the motor and vfd to another output on the board. works fine

PLEASE HELP

[dialfonzo]

Hi assaf,

The best for you would be to contact the VFD / Motor / Controller companies to get support for their products.
Since we do not sell any of those, it will be hard to troubleshoot.

What you can do is swap the VFD to another motor to see if the problem is actually moving too.
Also verify the VFD settings with your LCD to confirm they are the same.