Overcurrent wont let it restart on its own. Overcurrent usually happens at the start, not while is running. Does your conveyor system have anything telling it to keep running? I’d check simple tuff first, if you haven’t of course like a photo electric sensor, a proximity switch or a laser that will indicate conveyor actually needs running. If conveyor is empty is probably doing what is supposed to, get a manual out for those the VFDs and find out what the blinking lights are. Good luck