how to control electric motor with control ammeter

The current the motor draws is linearly related to the torque presented at the output shaft.

Limiting the current will cause the motor to stop or to stall. Most variable speed drives can be programmed to do this. Is that what is wanted?

Hi Clement and PWSlack,

I think he has two motors and he wants to start and stop the feed motor based on the load of the other motor.

In the case of an on/off type of thing, you may have problems with starting and stopping the feed motor. Shop around--there will be a lot of different types.

If you have the resources, I would agree with PWSlack and suggest you put a programmable VFD with analog inputs and get a current transformer with a 0-20mA (or 4-20mA)/0-10VDC output--Check Dwyer.

www.dwyer-inst.com/Products/TOC.cfm?MainCategory_ID=6&iCurrentCategoryID=216

With a VFD/ASD you would be able to program and control the feed with some precision and be able to ramp the the speed up and down. This may give your mill drive motor way more effeciency and it will get you away from starting and stopping the feed screw across the line (provided the material is somewhat metered).

Is control the feed out of the question, to stop the over feeding ?

Hello friend,

It seems like you have two motors where the main mill motor rated at 45KW is fed thro' small feeding motor.

what you need is to control the feeding motor in order not to overload the main motor. This can be acheived by coupling a clutch to the feeding motor and controling the clutch DC supply through an analouge meter having two preset values (High/Low) for engaging and disengaging of the clutch. in this way the feeding motor continues running at all times.