Wiring Diagram check

**routercnc** · 17-01-2016

I think you mean the 'star ground'. This means all grounds from shields etc. all meet at one point, and this one point is then connected to the ground from your mains cable.

I'm not an electronics whizz but I think the idea is to avoid 'ground loops'.

Here is one of my older diagrams (a few changes since) - see the yellow cables which all join at a single point. This is then connected to the mains cable earth.

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Here is a picture of my control cabinet - ground is yellow and green. You can see that all of these cables meet up at a group of terminal blocks that are right next to each other (this is my star ground point). Because they are special earth terminal blocks they also connect to the metal DIN rail underneath which effectively joins them all together at that point. The middle terminal block then has a single wire which goes back out to the mains earth.

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Note that my VFD is completely separate (separate mains cable, shielding and earthing), but many people run everything off one socket.

**eurikain** · 17-01-2016

Thanks routercnc for you explanations :) your cabinet looks great ! I've actually got the same DIN rail mounted terminal blocks / relays / yellow-green terminal blocks :)

My question was more about how you stop the spindle. On your diagram, I see the line that goes through the relay and connects to FWD and FVD control interface, but what powers it ? Is that wire getting 24V, or is it just a loop on the VFD itself ? Here is how I understand it: when you power up everything, the spindle can move forward because the loop DCM/FWD is closed. If the relay goes off, the circuit opens and the VFD stops the spindle because its DCM/FWD loop is broken. I am wrong again ?

Also, could you take another photo of your linear PSU please :) ? I like the way you did it but the resolution won't let me clearly see how you connected the capacitors together (it looks very neat).

**JAZZCNC** · 17-01-2016

Originally Posted by eurikain

Here is how I understand it: when you power up everything, the spindle can move forward because the loop DCM/FWD is closed. If the relay goes off, the circuit opens and the VFD stops the spindle because its DCM/FWD loop is broken. I am wrong again ?

Correct works exactly like that. Very simple.

**routercnc** · 17-01-2016

As Dean says just a simple circuit connecting 2 wires together.

Away from pc and workshop but there are photos of power supply on my build log 'router mk 3' or something like that
Capacitor cables are one cable with the sleeve cut out at the right intervals then soldered to the terminals

**eurikain** · 18-01-2016

Originally Posted by JAZZCNC

Correct works exactly like that. Very simple.

Very simple but not obvious for me haha ^^

Originally Posted by routercnc

As Dean says just a simple circuit connecting 2 wires together.

Away from pc and workshop but there are photos of power supply on my build log 'router mk 3' or something like that
Capacitor cables are one cable with the sleeve cut out at the right intervals then soldered to the terminals

Smarty pants ! That's a great way to do it ! Just need to get the hand at cutting the sleeve without cutting the wire haha :) Thanks for the advice ! It makes things much more simple. Will 2.5mm2 cable be enough ? My friend that works for the Belgian electricity company says 6amps per 1mm2, so 2.5mm2 goes 15A, good bet right ?

**eurikain** · 30-01-2016

Originally Posted by JAZZCNC

Correct works exactly like that. Very simple.

Jazz, when looking at my VFD manual, it looks like instead of the FWD (which is actually labelled FOR) I should use the RST pin.. If I wire the FOR-DCM loop through the relay, the spindle will start automatically right ? I'm not sure that's the behaviour I want.. I just want to be able to manually control the start/stop speed etc with the VFD front panel, but automatically stop when the relay goes off. I know you're gonna end up thinking I'm dumb, but I promise I'm not that stupid haha :) Now, if using the DCM-RST loop, I guess it would have to be normally closed, so that when nothing's powered the spindle does not start, when the relay is on the RST line is off so the spindle can start/stop as I will, and then when power goes off (due to pressing the e-stop) the relay goes off and the RST line closes which stops the spindle.

**JAZZCNC** · 30-01-2016

Originally Posted by eurikain

Jazz, when looking at my VFD manual, it looks like instead of the FWD (which is actually labelled FOR) I should use the RST pin.. If I wire the FOR-DCM loop through the relay, the spindle will start automatically right ? I'm not sure that's the behaviour I want.. I just want to be able to manually control the start/stop speed etc with the VFD front panel, but automatically stop when the relay goes off.

Ok well same thing really just controling a different function and how you describe the relay etc is correct. BUT why wouldn't you want the software to Control ON/OFF if you have the abilty.? . . It makes life so much easier.!
You can walk away from the machine and Know it will stop the spindle when finished. It will Stop the Spindle between Tool changes and Start again when press Cycle start. Which is great when learning because it's common for people to push Cycle start after tool change then realise they haven't started the spindle.!!

**cropwell** · 31-01-2016

Originally Posted by eurikain

Jazz, when looking at my VFD manual, it looks like instead of the FWD (which is actually labelled FOR) I should use the RST pin.. If I wire the FOR-DCM loop through the relay, the spindle will start automatically right ? I'm not sure that's the behaviour I want.. I just want to be able to manually control the start/stop speed etc with the VFD front panel, but automatically stop when the relay goes off. I know you're gonna end up thinking I'm dumb, but I promise I'm not that stupid haha :) Now, if using the DCM-RST loop, I guess it would have to be normally closed, so that when nothing's powered the spindle does not start, when the relay is on the RST line is off so the spindle can start/stop as I will, and then when power goes off (due to pressing the e-stop) the relay goes off and the RST line closes which stops the spindle.

What you could do is use a two way switch with centre off. One way would switch the FOR-DCM directly and the other would put the FOR-DCM through a relay controlled by the BoB. That would give you three modes :- Fully ON,Totally OFF and Automatic. I do this for my Kress spindle and also my chip blower. I will probably do the same when I build the next machine with a VFD controlled spindle.

Cheers,

Rob

**Clive S** · 31-01-2016

Rob I see the trouble with this is starting the machine code with the switch not in the correct position and then not getting to the Osh#t button fast enough

**cropwell** · 31-01-2016

Originally Posted by Clive S

Rob I see the trouble with this is starting the machine code with the switch not in the correct position and then not getting to the Osh#t button fast enough

I agree, but when you have done it a couple of times, you learn

. I check the switch is in the correct position, but the 'always on' position is down, so you can hit it faster than the osht in my case. After having my finger bitten by the machine, it also helps my confidence to put it to 'off' whilst doing a tool change and restarting the code does not fire up the spindle, so I switch it to 'on' before continuing. My new Cam software puts out the M03 after a tool change though.