Centroid Community CNC Support Forum

Hello Everyone,
I purchased a PCTurn 120 a few years ago and finally get to see the end of this project. I will be controlling this lathe with an Acorn controller and 1ph to 3ph VFD. This motor has an external 3ph cooling fan for low-speed operation and it is 3ph as well. The main motor windings have thermal protection on each coil.
1. How should the cooling fan be wired? I think 3ph with no frequency change regardless if the spindle is low or high speed, so it will get its own VFD.
2. With regards to the Thermal protection of the main windings, I will use a leg of non-VFD 220v through the thermal protection and then to the 220v coil of a 2-pole contactor to shut the power off to the motor if the overload happens. The 2-pole contactor will have 24vAC on one pole and 24VDC through the other pole. The 24VDC is from the Acorn to detect and issue when the signal is lost, the 24VAC will control another contactor for the main spindle power.

Is my thinking correct?
Thanks,
Brian

It seems like that is more complicated than necessary. Just run you motor winding thermostat through an input and assign it to spindle fault. When CNC12 receives a spindle fault it will disable the spindle.

But would not a coil that has a 220V AC VFD modulated signal interfere and somewhat overwrite the 24V signal voltage that the Acorn would be putting out? I did think about doing it that way initially but was not sure it would work and still be safe for the Acorn controller. I watched several videos where they took a leg of 220 and ran it through the Thermal protectors the to the aux port of a contactor. Guess I am more scared of blowing up the Acorn. The only doc I have is what I attached to my initial request for help and it was lacking in explanation.

Brian

The thermostat is just a switch, it doesn't care what voltage is running through it. Either way works

Thanks tblough.

i moved this post into the acorn forum

Have you wired in the turret yet please? If so do you have any diagrams.
Thanks
Chris