Quote Originally Posted by JohnHaine View Post
What's the reason for the stop/start button? Is it actually the E-stop? Normally it's useful to keep the stepper drives powered up even in an E-stop, if you de-power them they lose up to a step depending on where they were in the microstep cycle.

According to the colour scheme the neutral bus and Ground Bus are commoned, I hope that isn't what was intended?
The latching stop and start buttons are to turn on and off the VFD and Drives. From what I've seen this seems to be a common setup. You are correct about potentially losing steps but generally a stop button will cut power to the whole system so I guess you would have to re-home and then run the operation again. I always have the option to just pause the operation within the software.

The first toggle switch from the mains supply is the main enclosure on/off

The E-stop push button after the main toggle switch is just something I'm adding in so I have something nice and big to hit quickly in case of an accident.

The neutral bus is not commoned, I'm not sure which part of the diagram caused you to think that (apologies I have little experience drawing these things up) but it is separate from the Ground bus