Running a VFD controlled motor with lower than rated Voltage setting

[KallH]

Hello I have a question about a VFD controlled motor.

I have an AC motor controlling a relatively constant torque load that has a rated torque far above the requirements for the system. Once in a while the mechanical system will jam causing physical damage to the system before any over protection is able to kick in. I would like it to be able to stall and trip before this happens. So for my question, am I able to simply reduce the motor rated voltage setting in the drive to below the rated nameplate to reduce output torque or will I also need to adjust the frequency to keep the same V/Hz profile?

If I do change these settings and the motor stalls, will there be any implications for the overload protection of the drive assuming I set the rated full load amps to the value on the motor nameplate?

It is using a fairly inexpensive drive, GS2 from automation direct which is fairly limited in overload protection settings from other VFDs I have used.

 

[KallH]

Yes I was more referring to the reaction speed of control system to stop the motor when it detects the increased torque/current. The digital outputs on the drive are mechanical relays which will have a slower response than a solid state output. If the power was removed from the motor, allowing to coast even from full speed I highly doubt there would be enough inertial force to cause any damage. As long as the control system can react fast enough to remove power when it does jam we will be ok.

As mentioned, my preferred solution is to remove the reason the system jams in the first place. It does not happen often (once every 1 to 2 weeks) but when it does it can cause damage. This will be more difficult and costly than changing the control system so that is where I am looking, plus that is where I am most comfortable making changes.

Next would be reducing the torque output of the motor just enough that the output is less than the force required to damage the system but enough to move the load, which is kind of what I was originally asking. Currently the VFD current from the display is only about 30% FLA during operation.

Lastly would be to rely on the protection functions on the drive which it seems is where I am at.