Documentation is all at:
and for maintenance see:
https://my.carbide3d.com/docs/maintenance/
I just power mine off w/ a switch on power strip it’s plugged into (but I don’t have a VFD — if there’s something specific on that it’d be in: https://my.carbide3d.com/pdf/VFD_Spindle_Kit_Install_Guide_v1.pdf )
EDIT: Note that that says:
Always press the Spindle Enable button to disable the spindle and flip the power switch on the side of the VFD controller to turn it off when done cutting
EDIT: Checking w/ folks I was told:
When the spindle is turned on and spinning never turn it off by the power switch. You need to stop it first before shutting off the electric power in order to avoid damage to the control board.