Control Cabinet Wiring

[Neale]

Greg,

the problem is that the VFD has two inputs. One for starting in forward, one for starting in reverse. It's not quite as simple as a changeover relay operating one or the other - you need to be able to switch one for fwd, the other one for rev, or neither to stop the spindle. Your BOB only has one output - which it states is for spindle on/off, not direction switching - and even if you take that to a second relay with changeover contacts, you still do not have a true "off" position. To be honest, I don't think that that BOB is going to do what you want unless it has a second output somewhere. BOBs with only one relay output are quite common (the one in my first router was the same) but you need something with two separate outputs to get fwd/rev/stop switching. You cannot use the changeover relay contacts to provide direction switching and rely on the 0-10V analogue speed output to stop the spindle. If you are changing tools in the middle of a job, you want a stopped spindle to definitely stay stopped, and not suddenly decide to creep a bit because the analogue signal has drifted a bit.

Actually, looking more closely at the BOB connection diagram, it might be possible to do what you need. You have shown yourself using the "spindle control" output pins. However, there is also an option to select between "B axis direction" and "relay output" on one of the pins on the bottom row (as per your picture). This is controlled by a jumper next to the relay. I can only guess at how the actual switching is arranged, but it might be possibe to configure things so that one of these drives "VFD fwd" and the other "VFD rev". But without knowing a bit more about the BOB internals and how it does its switching, I'm not sure with the information available exactly how this could be arranged. You could scrap your additional relay and transistor in this case.