CNC electric supply

[Martin Wasner]

In my part of the world it is a huge code violation to run mixed voltages in the same pipe. Special considerations aside.

Standard practice here for commercial.

[Darcy Warner]

Standard practice here for commercial.

I only see it low rent shops, never in bigger nicer operations. Why cant everyone use buss ducts.

[Martin Wasner]

I only see it low rent shops, never in bigger nicer operations. Why cant everyone use buss ducts.

Because they want a quart of blood, your first born child, and three years gross revenue to buy the parts?

It doesn't get any easier once it's in though

[Jon Snider]

Bringing this back up for one more question. Talking to Phase Perfect today (although still not sure if I’m going with them or an American Rotary ADX), I was asked what 3 phase output voltage I wanted. I assumed 240v but was told CNC’s can take a whole range, even with some 208 v machines. Since some of my old iron can use 208 this might work, but most of those machines have greater tolerances and I’m thinking 240v is a better overall option. Since I’m putting in 3 phase for everything now, but have no current idea what CNC I’ll eventually have, any advice on typical voltages?

thx.

[Martin Wasner]

If you buy new, you should be able to spec whatever you want. Should is a pretty big word though.

My router, the guy had it on a step up transformer since he didn't have 480 in his shop. Anything I can get on 480 now, I do. But, a whole mess of euro stuff can't be switched over and wants to remain on 208.

So whatever you pick now, unless it's both, you're likely going to be wrong.

[Brad Shipton]

Unless you get into the size of CNC that Martin has, most of us run a spindle less than 10hp. I have a 10hp spindle and it runs on a 60amp 220V breaker with a VFD. I would be shocked if I ever draw 25% of its FLA. For me, upgrading to that spindle turned out to be silly as my machine is not stiff enough to push it fast enough to use that Hp. I was convinced to upgrade by a tooling salesman that does not quite understand the entry level machines. It was not a huge cost to upgrade, but 5hp would have been fine. If you want to use HSK tool holders, then you need to be 12hp+ as that is the smallest spindle I believe HSD offers that in. HSK is the most common in the industrial world.

The bigger concern for power is the vacuum. When you start talking about an industrial vacuum, those are real power hogs unless you stick to the single phase options like most on SMC. 10Hp is a start point and 20 - 25Hp vacuums are not uncommon. Those will draw exactly what the motor tags say at some point.