Your machine says 220 +/-10 but your 240 supply is also going to be +/- something so it can go over 240 so you are right on the edge; as you have discovered. Welders can cause surges and spikes, especially big welders.
I don't think it is a good idea to have things like welders on the same supply transformer as the CNC equipment. If you do not have any transformers inside your place then everything is on the same transformer that is somewhere outside.
I would look into getting a buck-boost transformer for the machine. That will allow you to adjust the 240 voltage down toward 220 or 208 and the transformer will dampen surges and spikes from the welder. |