Centroid Community CNC Support Forum

Hi Marty,

Thanks for the reply, I am just finishing up the control cabinet wiring (after bench testing everything) and the AC wiring is basically the last bit to finish up. So I haven't ran wiring from the DIN rail yet.

All of the outlets in my shop are on 20amp circuit breakers.

I would appreciate any suggestions as to where in the wiring scheme to add any fuses or breakers.

FKreider wrote: ↑Mon Aug 24, 2020 12:30 pm Hi Marty,

Thanks for the reply, I am just finishing up the control cabinet wiring (after bench testing everything) and the AC wiring is basically the last bit to finish up. So I haven't ran wiring from the DIN rail yet.

All of the outlets in my shop are on 20amp circuit breakers.

I would appreciate any suggestions as to where in the wiring scheme to add any fuses or breakers.

You suggested you were done but did not add a disconnect (On/Off) switch. You would fuse the incoming line to the control cabinet. That fuse size is based on your load. Further, you wiring size needs to be rated to that fuse size. I do not know the details of your build. So I can't give you specifics.

Look at the Acorn system schematic for ideas.

Ok... still trying to finish wiring my electronics, 6 month old baby at home has been a major distraction!

Now that its been a while since I looked at the schematics I am struggling with the Acorn to BOSS15 spindle controller wiring, thought I had it figured out but I'm scratching my head now.

I put together this quick schematic, can anyone tell me if I am on the right track and help "fill in the blanks" ?

Have you tried KBSI-240D in the search box? A lot has been discussed on its use.
Franco CNC on YouTube also discussed a similar application.

Hi Marty,

I think I can probably figure the KBSI portion out, I am more concerned with the relay wiring for the spindle control, does it look like I have it shown correctly?

It appears that the "common" from terminal 1 needs to loop back around to terminal 5?

The BOSS spindle manual that I posted earlier in this thread says not to use terminal 7 so I would think the KBSI output needs to go to terminal 5 and 6 but then what do I do with the "common"?

I found this: http://www.kbelectronics.com/data_sheets/kbsi240d.pdf
Though it shows for one of their KBIC drives, it should apply to yours.
Looks like you would use:
One Relay output for FWD/REV and assign it to VFD DIRECTION
One Relay output for Enable/Disable and assign it to VFD ENABLE
And take the Run/Brake circuit through an Estop Contactor controlled by Relay 1 and assign to NoFaultOut


Just my suggestions....

Looking at your BOSS manual, did you not find this on VOLTAGE FOLLOWER? This should be your answer for speed control from the KBSI-240D: You could prove the theory with a 1.5 battery....or a DC bench power supply as the voltage source....

Test everything with meters before connecting your drive...

I actually saw that "voltage follower" section last night but wasn't sure if it was what I was looking for- thanks for the heads up!

Will report back once I am able to wire and test.

One more question- so its clear that the (-) output from the KBSI goes into terminal 1 on the spindle controller however does this also become the "common" the manual tells you to short through the relays for each function? (FWD/REV - Enable/Disable - Run/Brake)