Quote Originally Posted by njhussey View Post
I thought I read somewhere in a discussion that cutting power to the VFD whilst it was running was not a good idea and that the best thing to do was fit a timer to then switch off the power after it has been told to stop by the controller?
That's why the decent manufacturers have an E-Stop input on the VFD, you can configure different ramp down and braking for Stop and E-Stop, if you have a braking resistor the E-Stop can be startlingly fast.

An electrical engineer I used to talk to was discussing ramp down time for a circular saw E-Stop with his boss and was instructed to make it stop as fast as possible, his boss arrived later that day for official commissioning and a demo an was surprised to find Chris outside the workshop door with the E-Stop on a long lead, his boss paid for the replacement blade and the floor, wall and ceiling repairs.