some help on understanding torque settings needed

[samv76]

Hi all,

I have some trouble making sense of the settings in my Sevcon gen 4 contoller.
The motor it is driving is a 3.9Kw Parker motor, that according to the sticker on it, delivers 15Nm of torque.

In the motor controller however, the max torque is set to 80Nm.
i am sure there is some conversion calculations involved as the belt drive uses a 22 tooth front sprocket and a 84 tooth rear sprocket.

But i cant figure out how they got to 80Nm. Even more strange is that in the drive profile, the max torque is limited to 37%.. so that would be 37% of 80nm = 29,6 Nm?

All this is a bit confusing TBH.

 

[amberwolf]

What kind of torque sensor does the system have on it, to tell the controller how much torque there is? And is the controller setup correctly to read that sensor accurately?

If there isn't a sensor, then the controller cannot know the torque of the system, so those settings should be irrelevant.


If you have complete information about the motor's characteristics, of how much current produces how much torque under what current flow and load conditions, and the controller knows all that, then it can calculate the torque, but without that, it doesn't know.


Regarding the mtoor's torque label...that is only under the specific conditions it was measured at. If it has higher voltage, or higher current, or lower v or a, then it won't produce that exact amount.