You are thinking of hooking them together. Don't.
What you want to do is a project, not an application. Manufacturers only cover applications not projects. The arduino combines applications into projects. The Arduino will be in charge of reading the current and controlling the motor.
The control of the motor will require two relays, one for power and one DPDT setup to control/reverse direction.
Connect the the ACS712 to the analog input. Use the analogRead to get the current, then use an if statement of the current reading to detect the current limit and stop and/or switch directions. If you do not stop the motor before reversing direction, you are going to see huge current readings as the magnetic field collapses and the motor reverses direction.