Wow this thread is brutal.
There is such thing as machinery that runs on 4kv, 3 phase though. You see it in old factories and I think some ships use it.
In MA state law is that you can rubber glove 35kv out of a tested insulated bucket. You won't turn to toast. In some places you can still bare hand 4kv out of a tested bucket. I saw once on the history channel that you can bare hand 75kv(against the law, but if it were to happen by accident) out of an insulated bucket, but I don't believe it. I think they only said that because that's what OSHA makes use use for voltage to test buckets. I bumped 7.9kv(13.8 phase to phase)above my rubber sleeves by accident out of a bucket and it hurt really bad. High voltage doesn't hurt birds because they are small and insulated. The Human body reads as load so it hurts like hell but can't kill you if insulated up to certain voltages, higher volates will burn you even if insulated because you are load. Sorry to add to the off topic-ness, but you will not turn to toast unless you're touching ground, neutral, or another phase. 13.8 voltage will blow your arms off if you happen to touch two phase and it will pass through a pin hole in rubber gloves. So you don't touch anything but the phase you work on and your bucket.
Bottom line is higher voltage is more efficient, but costs pretty much the same as far as your electric bill is concerned. Like someone said, even if you don't know anything about electricity, use a 240v saw next to a 120v saw and see which works best. It bet you'll go with the 240v saw. The only reason 120v is better is because you probably already have plenty of 120v outlets with nothing plugged into them. You're still getting 240v volts from the same single primary(or two if it's delta primary.) going into the transformer. They could put a meter on the primary side of a transformer feeding just your house and you will be charged the same as the meter on the side of your house house no matter how your house is wired.
