1354080185[/url]' post='
1019346']
1354070558[/url]' post='
1019312']I am not sure that the original OP question was ever answered. We hit all around it and learned some good things but the question was,"What happens to the neutral current? Does it go to earth ground as it passes each pole or does it go all the way back to the substation?"
SHORT ANSWER: No need for the current to flow to the sub-station, why? The power for your home comes from the line transformer that steps-down the line voltage to 120/240 volts.
Any measured current flow is only to that point.
Difference between 3 wire & 4 wire three phase power is easy to understand. The additional conductor allows the use of one of the line phases paired with the neutral for a lesser voltage. Phase-to-phase 480v 3-phase will now offer up 277v single phase. This 277v single phase can now be run through a transformer for 208v & 120v.
Three wire 3-phase is the best for motors & equipment as the motors run more efficiently & typically uses about 1/10th the power of a 120v motor of the same hp rating. The motor's windings being the same value, do not suffer from line imbalance (power loss factor), so no neutral is required. Changing the motor rotation is easy as pie... flip any two phases.
I forget anything?
