Which terminal do I hook the panel ground wire to on my VFD?
Both the motor frame and the chassis or mounting bracket of the VFD should be connected to the ground terminal in the power distribution panel. The neutral of the 120/240 system should be connected to ground only at the service panel. The ground point at the service panel should be connected to a nearby ground rod driven into the ground. What is the PE terminal in the VFD connected to if not the chassis or mounting bracket? It shouldn't be connected anywhere else. Is the manual that you are looking at available online?