text: <s>[INST] Load sharing and back-up I am running two PF70EC VFDs to two motors (w/ encoders) driving a single drum and am wondering what is the best way to have them load share, also if for some reason one motor or VFD goes down the other will take over. Motor are large enough to easily handle the load individually, but we require redundancy for this project. I have seen several solutions on load sharing, but none of them seem to lend themselves to redundancy. [/INST] I would use the speed trim method shown in the document that you can download from the literature library. http://literature.rockwellautomation.com/idc/groups/literature/documents/wp/drives-wp001_-en-p.pdfFor the speed trim you would use the Process PI function in the drive and limit the output of the Process PI loop to 10% of nameplate rpm. If you have some kind of supervisor control, you can turn off the PI loop if the other drive faults. We have used this method for years with great success. It will take a little bit of work to set it up and tune it. Curt PlettEngineering ManagerSystems Interface Inc. \\n </s>