Would you call that standardization ? Mains power supply voltage seems to be sure one of the least standardized world resources. Vitor Finkel [email protected] P.O. Box 16061 Tel (+55) 21 285-5641 22221.971 Rio de Janeiro Brazil Fax (+55) 21 205-3339

 

We've proceeded far beyond the original query. However, Vitor Finkel's response reminded me of a study I once conducted years ago. It was for an LV distribution system major-size oil refinery of the future. I chose 831Y/480 Volts based on what was then available as 'optional' equipment in the oil patch (oil field exploration and production). There was major economic incentive (much less copper) at the time. It was rejected by proponents of the "leave things as they are" mind-set. I'm quite sure that in light of the relative size increase in today's industrial electric systems, there will probably be an even greater incentive! If interested, contact me! Regards, Phil Corso, PE (Boca Raton, USA)

 

The original question was why 110 vac in North America or 220 vac in Europe and rest of world. As far as I can determine Thomas Edison made the original choice of 110 vdc (that's right DC voltage) because that was the highest voltage that he could use with a carbon filament and get enough light to beat gaslight illumination without blowing the filaments in too short a time. When Westinghouse began to compete with his ac system (around 1886) he most likely used the same RMS voltage because that was what the market was familar with.

In Europe the Berlin Electric Works went from 110 vac to 220 vac starting about 1900 because the city was already wired up and by going to 220v it allowed the company to increase its capacity without rewiring the whole place. Even replacing the lights and motors of its customers was cheaper than rewiring the whole city. 220vac useage spread in Germany as interconnections enforced standardizations, then in Europe and then most of the rest of the Old World but was never taken up in North America.

 

True about the power loss. But V = IR is the "voltage drop" in the line as a result of the current I flowing and R the resistance of the line. So there is voltage loss. Remember Thevenin's theorem?