# Abb acs550



## youngebuck (May 27, 2015)

Hey guys I know this is a very simple task however this is the first ABB drive that I have encountered in the field.

I want to control the speed of a conveyor using a 10K ohm speed pot. I would do this by changing parameter 9902 to 8 and using AI1, AGND, and the 10V on the terminal strip.

My question is, would I be correct in doing this from the torque control macro, and are there any other parameters that I will have to change by doing so?


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## JRaef (Mar 23, 2009)

youngebuck said:


> ...
> I want to control the* speed *of a conveyor ...
> 
> My question is, would I be correct in doing this from the *torque *control macro, ...?


The drive can do speed control, or it can do torque control. You said you wanted to control the _speed _of the conveyor. That would be _speed _control, not torque control.

Torque control is when you must control the TORQUE applied to a motor, regardless of the speed. The classic example is a wire winding application. As the winder spool increases it's diameter with the wire, the linear speed at which the wire travels is changing because it is based on the circumference of the spool, which is getting larger. So if you tried to control the SPEED of that spool all the dime while it is dynamically changing, you might end up applying too much TORQUE to it and it stretches the wire, or you might not apply ENOUGH torque to it and wire starts flying everywhere from backlash. So by maintaining a constant TORQUE on the spool shaft, the speed goes wherever it has to, with the torque staying the same.

Without knowing what task your conveyor is doing, I can't say if you want speed control or torque control, but you actually said SPEED, so I'd say stick with that.


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## erics37 (May 7, 2009)

If all you want to do is speed control a conveyor motor manually with a 10k pot then I don't know why you would use the torque control macro. JRaef discussed that already though.

The ABB Standard macro would likely work just fine, depending on what kind of control scheme you've got going on. Potentiometer would get wired into AI1 et al. like you said.

If your setup is fairly straightforward you could probably just program your motor nameplate data in parameter group 99, wire your starts, stops, forward, backward, PLC enable, etc. into your digital inputs, and then fire the thing up. Check parameter 1103 for your speed reference - if your pot is wired into AI1 then make sure AI1 is selected.


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