Quote Originally Posted by Kitwn View Post
The cooling pump is on the same mains switch as my VFD and runs continuously which allows better post-job cooling in my opinion and so doesn't need a BOB output. The one output is used as the spindle start output but is also used to switch a mains relay which starts the dust extraction.
Often VFD's provide an output Relay which you can use to turn on the water pump when spindle starts or have it turn on another relay which starts water pump and Vacuum when spindle starts. Better than having a pump running all the time VFD is on but spindle not spinning.

You will probably have to change a parameter in the VFD because often the relay is set to activate when a fault happens but can be set to turn on when start command is given.