Quote Originally Posted by JAZZCNC View Post
6A for Control Signals.!!!!!. .

Don't worry Bee it will be fine. These spindles at full load only pull 8A. In practise and while heavy cutting they actually rarely pull above 5A. 0.75mm2 is rated 6A and this is very conservative rating. Again in practice and for the very rare occassions you do pull full load of spindle/VFD it will easily allow to pull 8-10A without any trouble. In case of Short Circuit the VFD it's self will protect you with it's Max current setting and then you have the Fuse.
You can't ONLY go only after currents, if that was all that mattered we could use hair thin wires for all type of communications. You are blindly staring at one parameter only.

Generally speaking, yes, 0.75mm2 is enough for most cases for the spindle, but why use something as thin as that if 1.5mm2 is safer, stronger, not much heavier, better suited for the purpose and hardly much more expensive. Can you come up with ONE good reason other than most people don't continually use up more than 5A?

I chose 0,75mm2 for the control signals because that is what I have, apart from 1.5mm2 and FTP CAT6 cables (0.5mm2), so I chose the 0.75mm2. The FTP cable would be good as well, but I like the Ölflex cable more, it is easier to handle for the purpose.