May 09, 2018· Then program the VFD for 120 Hz, and use the listed running speed on the motor's plate, which is 3430 RPM. No worries about damaging the motor using 120 Hz? Do I need to start the motor in two steps, first 60 Hz, then roll up to 120 Hz? I tried the following and it didn't work at all: Set the drum switch to 1/2 speed. Program VFD for 120 Hz.