Wiring plan for upgrading my chinese cnc electrics enclosure, have I missed anything?

[paul4523]

Upgrading my OMIO X4 machine to an AXBB-E controller and new enclosure. I'm a novice and have tried to learn as much as possible in order to take on this upgrade project. This is my planned basic wiring setup, would appreciate any feedback

Few notes:

• Double-shielded cable will be used for all signal cables and they will all be grounded and terminated to the Ground Bus bar.
• 5 Pin GX16 connections will be used so the motor cable will also be grounded
• VFD & Power will be in top half of enclosure and AXBB-E & Stepper Drives will be in bottom half to try and keep distance high and low voltage cables
• Turning on mains power switch will only power the 24v, 5v, Fans & AXBB-E
• Pressing the latching Stop/Start button will turn on the contactor which has a 24VDC coil that will then feed power to 48V, VFD and Stepper Drives

[JohnHaine]

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?

[paul4523]

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

[JohnHaine]

On my lathe the e-stop turns off the drive and raises an E-stop condition on the controller. This halt execution but the drives remain energised and the reference is kept.

My point was that you have used the same wiring colours for mains live and neutral and supply positive and negative (Ground). You might use brown and blue for live and neutral; or other colours for pos and neg. Then it would be entirely clear.

But generally a good approach though perhaps overkill!

[paul4523]

Im curious, how would you wire an e-stop so it turns off the drivers but still keeps the motors energised? The motors take their power from the drivers so cutting power to drivers cuts power to motors also right?

Sorry for the confusion I have re-coloured the diagram to correctly show the live and neutral feeds, hope that is clearer now

[JohnHaine]

My estop is wired to remove power from the spindle drive and assert an estop condition to the controller - there should be an input on the AXBB to do this. This immediately stops pulse generation but the drivers remain powered and so the motors retain position.