1 or 2 dedicated 120VAC circuits for my CNC?

I wanted to get opinions on whether it is worth it to provide 2 separate 120VAC circuits (from the panel) to my CNC? 

To start I will not be running a inverter/spindle. I will be starting with a router but do have plans to upgrade at some point. I know that running the logic from its own PSU is preferred but was wondering if there is any advantage to running two separate AC circuits? Or is running them off of separate PSU's/breakers good enough?

I only ask because I am planning to run a dedicated circuit to the CNC anyway, so running an extra is very little extra effort.

Thanks

Sending two phases is OK, just in case you might need it later.
Sending 2 wires from the same phase is redundant, still might come in handy.
Off topic but still on topic:
I will be missing 3 phase power we have here when and if i move to USA.
We just plug things in, up to 40KW is still OK, legally 22KW in every house!
We can charge a Tesla overnight by just plugging it in, we do not have Tesla's, or any electric .... wait we do have some Taxi cars that are electric, about 100 in total, in the whole country!

tommylight wrote:

Sending two phases is OK, just in case you might need it later.
Sending 2 wires from the same phase is redundant, still might come in handy.
 

Well it is my understanding that residential power in the US is not 2 phase, although the 240V (single phase) coming in is split into two 120V phases (split phase).

With that said, I am talking about running two circuits, from two 20amp breakers in the panel to the CNC. I guess that would be running them both off the same phase. So there is no advantage in regards to keeping the noise from certain components separate from others by running separate circuits off the same phase? I know they all go back to the same panel. 

Shawn

In US power is a mess!
No advantage there, it is just a convenience in case you require more power later.

No, there's no advantage noise-wise.  Two 20A 120vac circuits off the same breaker box is basically like running a single 40A 120V circuit with heavier conductors.

You can handle noise inside your control cabinet by keeping the AC stuff away from the DC stuff, adding filters and a line reactor upstream of the VFD (if you have one).  Line power comes in through main disconnect, through the main circuit breaker or fuse, then to a junction block.  The AC-DC PSU gets fed from that (with it's own breaker/fuse), then another (fused) branch through a line reactor & EMI filter to the VFD or servo drives (or other noisy component).

You can even add sheet metal paneling inside the cabinet (if you've got room) to shield radiated noise from noise-sensitive dc signal circuits.

Use shielded cable for all analog conductors, encoder cables, and the HV stuff like servo power cables and VFD to motor cables.  Ground all shielding per the component MFGR.

Use 24vdc for signaling and control circuits where possible - much more resistant to low voltage ripples/EMI than 5v circuits.

My setup is very basic to start. It is just a CNC router. I am designing my cabinet to where the 3 PSU's are all on one side of the cabinet separate from the low voltage.

I have a 60V PSU supplying the motors. A 24V PSU supplying the logic (Mesa). And a 12V PSU for the cabinet fan.

If I were to add a inline EMI filter, where would be the most effective place to install it? Or do I need one if I am not running a spindle at this time?

I have been meaning to ask about surge protection. Is that a necessary component as well?

Thanks