Denford Triac VMC with ATC Conversion / Fix

[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

[Chaz]

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

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?

[Clive S]

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

Yes that would be correct. Clive

[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.

[Chaz]

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.

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

[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.

[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.

[m_c]

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.

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.