Hello - I am in the process of building a dedicated room for my Altmill 4x4 with 220v Spindle that will be arriving soon.
Sienci states “We recommend allocating one 15A 110V/120V circuit for the machine and one 220V/240V circuit for the spindle. Computer and dust collection can go on any of the two circuits as needed.”
It does not state what amp dedicated circuit for the spindle.
Much appreciated if anyone running a similar setup can give advice for the best way to run electric or an ideal setup. The room will be approx 10’ x 24". Besides the CNC, no other heavy duty tools will running. I would likely be adding a dust collection unit at some point (shop vac to start out).
I would never suggest to share a sensitive, pricey piece of electronics with a high power device such as a dust collector or table saw or what-have-you. If you happen to blow a fuse because of the high power device, you will have lost any project that was running on the CNC. There is also the issue of voltage drop when the device is turned on, voltage spike when the device is turned off and general noise.
If you are building a new setup and have an electrician (or DIY) do new electrics, do yourself a favour and have at least one additional circuit for devices other than your CNC. The incremental cost is insignificant. Do consider making the circuit runs 3 conductors (ie hot, hot, neutral). Again, minor incremental cost and you don’t have to hook up the second circuit right away but the line is in the wall which in most cases is the majority of the cost of any future upgrades.
In North America, unless otherwise specified, you can presume that both 110v and 220v home/shop/garage circuits default to 15A; the wiring is cheaper, no need to over-engineer things. If the power handling matters, count on the designers to call out the need for the more expensive wiring and outlets.
The difference between 15a and 20a is the use of 12ga wire instead of 14ga, the breaker used in the fusebox and the outlet prong patterns (parallel -vs- a T-slot); don’t worry if the smaller 14ga wires are already run - 220v/15a still delivers a lot of power - 3.3kW, compared to 220v/20a at 4.4kW. Both will power the Sienci 2.2KW ER20 220v spindle without breaking a sweat.
As others have said, you probably want to run a dedicated circuit to your CNC. You may also want to do the same for your computer and SLB-ext (that can happily share an outlet) - these sensitive devices do not like sharing a power feed with an electrically noisy dust collector.
I have two circuits for the Altmill. First is the 120V 20A for the Altmill computer and my controller PC, and 220V 20A for the spindle. My dust collector (shop vac) is on a different 120V 20A breaker. If that helps.