Thread: Milling Machine as a Drill Press?

Regarding the power questions I'm a complete amateur. I was definitely thinking about single phase power, so I know that will severely limit my options.

Originally Posted by FenceFurniture

Just a slight but related digression. If USA 3 phase is 230v, and ours is 415v, that means the power same machine in the USA will need to draw almost 2x the current. Doesn't that make it nearly 2x the danger? (as I understand it, it's the Amps rather than the voltage that gets you)

Hi Brett

as far as I can make out, US wiring comes in 2 different "flavours", for want of a better descriptor.

Domestically, the most common is 120V (nominal) -- which for 3 phase is 208V. Depending on where you live the nominal voltage can be 110 or 115 or 120 -- I'll leave you to work out what 110 and 115 are when multiplied by the square root of 3. For comparison, in Australia the nominal voltage it's 240/415.
To complicate matters, most houses will have at least one and possibly two 220V outlets (for the oven and clothes dryer). 220V is achieved by running two 110V actives (plus neutral and earth) to the receptacle the appliance plugs into. This allows the appliance to draw twice the current available via a single phase circuit, but doesn't make the motor 3 phase. I think the equivalent arrangement in Australia is to run a dedicated 15 or 20A circuit to the appliance.
I think -- note "think" -- that in the US the step-down supply transformer is much closer to the end user than is the case in Australia. Where I'm currently living, every street seems to have its own transformer, while back home transformers seem to power whole suburbs.

The second US voltage "flavour" is 227/480. You can get single phase 277V lighting and I suspect the standard US industrial 3-phase motor is 480V.

I fell stupid, I live here in the US and work at an automotive factory. I know their lighting here does run on 277 volts that's what electrician told when I worked with him. Most of our big mills and lathes run on 440 volts. Some of the older smaller machines may run on 240. We had some equipment from Germany that electricians had to modify because of voltage difference. House hold stuff is just as said, everything mostly runs on 110 except clothes dryer, some heat and air units, cooking ovens, and maybe water heaters. I have an air compressor that runs on 220. I think if someone needed to operate 3 phase or maybe 440 volt equipment, then the electric company has to install a different transformer. I hope this helped a little. I hate I sound like stupid American, but I can find out if any one needs to know.