Today, while commissioning a new winder (which had been tested by the manufacturer in its plant), the winder was started with no tension feedback. Within a second, tension rose to over 6 PLI. Thank heavens for E-Stops.
For heavy, strong webs like ours today, the web will not break, but the machinery may. Lighter webs will break.
Either condition is to be avoided. That is, we should avoid over-tension, over-speed due to the loss of tension feedback. The way to do this is to test the load cells statically prior to running. Then, start with a very low tension setpoint and very low authority to change torque or speed.
A big reminder for me and others.