Denford Triac VMC with ATC Conversion / Fix

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Originally Posted by Clive S

Neutral is not earth In the UK the earth is bonded to the neutral in most cases but not always.
The ground in your case is a central point where all the screens and ground are connected together in one place (star point) and that point in connected to the general earth connection. This is to try and stop ground loops. ..Clive

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Ah, sorry, mistook 'star point' as the star of a 3 phase system which is commonly earthed. Thanks, understood what you explained.

Out of interest, my drawings show the encoder shield only being attached on side and from speaking to a colleague this morning, that seems common practice (not to earth both sides of a shield). Would that be correct based on the collective experience here?

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Out of interest, my drawings show the encoder shield only being attached on side and from speaking to a colleague this morning, that seems common practice (not to earth both sides of a shield). Would that be correct based on the collective experience here

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Yes that would be correct. Clive

Been away for the past week (my Golden wedding aniversary celebrations?), so sorry to be harping back to one of the non technical points. If your motor is marked as 230v 3 ph you can almost certainly run that coolant pump on single phase. Set the motor block connecters to Delta and either use a vfd or trick the motor to run in quasi 3 phase using a couple of caps. I have been running 3ph motors on 230v single phase for over 20 years and have never had any problems. It may be neccessary to use a separate switched cap for starting. If in any boubt, cap values etc. you can PM me. Your project is looking great. Well done. G.

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Originally Posted by GEOFFREY

Been away for the past week (my Golden wedding aniversary celebrations?), so sorry to be harping back to one of the non technical points. If your motor is marked as 230v 3 ph you can almost certainly run that coolant pump on single phase. Set the motor block connecters to Delta and either use a vfd or trick the motor to run in quasi 3 phase using a couple of caps. I have been running 3ph motors on 230v single phase for over 20 years and have never had any problems. It may be neccessary to use a separate switched cap for starting. If in any boubt, cap values etc. you can PM me. Your project is looking great. Well done. G.

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Thanks. I did buy a starting cap from Maplins on the weekend. Need to get to the point that I can install it. This is what I bought,
2.5µF 440V Motor Run Capacitor

You probably need a starting cap and a run cap. I actualy use a little timer that switches the start cap in for about one second, but the value of the caps you use is dependant on the motor power and if the motor is stating under load etc.. This system does not give a true 3ph, but a "quasi" 3ph, however for a coolant pump I am sure it that you will never know the difference. G.

What is the general consensus for wiring the Emergency Stop Relay. Keep this and its function (X Y Z extreme limits) or wire into the CS Labs directly and control from there?

Currently on activation it stops all drives, the spindle, the coolant pump and the ATC. It works and I am inclined to leave it in place as it is.

Keep it as is, but feed an output from the relay into an input on the controller to tell it you have an estop state.

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Originally Posted by Chaz

What is the general consensus for wiring the Emergency Stop Relay. Keep this and its function (X Y Z extreme limits) or wire into the CS Labs directly and control from there?

Currently on activation it stops all drives, the spindle, the coolant pump and the ATC. It works and I am inclined to leave it in place as it is.

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Originally Posted by Chaz

What is the general consensus for wiring the Emergency Stop Relay. Keep this and its function (X Y Z extreme limits) or wire into the CS Labs directly and control from there?

Currently on activation it stops all drives, the spindle, the coolant pump and the ATC. It works and I am inclined to leave it in place as it is.

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Well I don't agree with Killing power because Limit trip isn't an emergency situation it's a positional error so no need to Kill power just Halt movement. SO I would have limits tied to the Enable signal on drives and Inform the Controller of a Limit breach.
This way you don't damage expensive tooling when the spindle grinds to halt inside of material because power is Cut.! Machine is just halted from continuing and you can recovery safely by lifting tooling out of material then reversing off the Switches using tempory overide.

E-stop is an emergency situation to the operator and this is when you want power stopped but often positional errors ie: limits are not life threatening or dangerous to user only potential machine damage and the Limit's prevent this in most cases.

I did wounce upon time think "Kill every thing" but experience as taught me it's not needed where limits are concerened and it's more a pain in the arse, esp with short travels with fast accelerating machine and expensive at times with unnecessary tool damage.

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Originally Posted by GEOFFREY

You probably need a starting cap and a run cap. I actualy use a little timer that switches the start cap in for about one second, but the value of the caps you use is dependant on the motor power and if the motor is stating under load etc.. This system does not give a true 3ph, but a "quasi" 3ph, however for a coolant pump I am sure it that you will never know the difference. G.

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One thing to be aware of when using this method, is you have to select caps that will provide reasonably matched voltages between the 3 legs when running. Achieving that with a small motor may prove to be a bit of a challenge, but you should benefit from the fact a coolant pump should have a reasonably steady load.
My main concern would be that the coolant pump motor is running near it's rated capacity, and when running from a static phase converter you risk burning out the motor if you try running it at high loads.

With a servo system cutting the power to the drivers if limits are activated is for safety in case you have a servo run away due to encoder loss, but cutting the enable will also work in this situation as well.

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Originally Posted by JAZZCNC

Well I don't agree with Killing power because Limit trip isn't an emergency situation it's a positional error so no need to Kill power just Halt movement. SO I would have limits tied to the Enable signal on drives and Inform the Controller of a Limit breach.
This way you don't damage expensive tooling when the spindle grinds to halt inside of material because power is Cut.! Machine is just halted from continuing and you can recovery safely by lifting tooling out of material then reversing off the Switches using tempory overide.

E-stop is an emergency situation to the operator and this is when you want power stopped but often positional errors ie: limits are not life threatening or dangerous to user only potential machine damage and the Limit's prevent this in most cases.

I did wounce upon time think "Kill every thing" but experience as taught me it's not needed where limits are concerened and it's more a pain in the arse, esp with short travels with fast accelerating machine and expensive at times with unnecessary tool damage.

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