Centroid Community CNC Support Forum

Is it a good practice to take one phase of my single phase 220 vac to make my 110 vac for my contact of the contactor or it must be a external 110 vac input ?

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You can, only if you also have a neutral, i.e. a 4-wire 240V service to the machine. If you only have a 3-wire service, two hots and ground, you should not use a single hot and ground to make 120V.

It's also important to keep your 120V loads balanced between the two hots. Optimally you want 1/2 of the 120V loads on each leg.

If you have a single large 120V load and do not want to run a separate 120V circuit, you should install a step-down transformer in the machine.

tblough wrote: ↑Thu Apr 03, 2025 3:36 pm
If you have a single large 120V load and do not want to run a separate 120V circuit, you should install a step-down transformer in the machine.

If you are on a 240v single phase input supply then the above applies, you'll need to install a step down transformer. They are very common in Europe (I think you are there?) as any building site uses 110v tools via the yellow portable transformer boxes.

As Tom stated, only if you have ALL 4 wires run from the panel. It's best practice to run all 4 wire for the exact reason you are asking. To be able to pull 110v from your 220v circuit. I do this all the time but I do run the entire CNC router and it's components on 220v for efficiency. Then I install a double gang duplex outlet on my machines so there are four 110v outlets for other tools need around a router like a sander, battery charger for battery powered tools or vacuum for clean up. Two outlets are on one leg and the other two on the other leg.