Articles tagged with: voltages

May23

Why So Many Voltages?

In 1887 direct current (DC) was king. At that time there were 121 Edison power stations scattered across North Americathe delivering DC electricity to its customers. But DC had a great limitation -- namely, that power plants could only send DC electricity about a mile before the electricity began to lose power. So when George Westinghouse introduced high-voltage alternating current (AC), made possible by the invention of the alternating current transformer by Nicholas Tesla, he could send electricity hundreds of miles with little loss of power. People naturally took notice. A "battle of the currents" ensued. In the end, Tesla's AC prevailed.

The electricity in the power lines near your home or business range from 14, 400 - 125, 000 volts!

The higher the voltage the higher the amount of power that can be transported in the same size of wire. Double the amount of power can be transported at 240V compared to 120V. Conversely, 240V has double the danger of 120V.


North America operates on a 120/240V 60Khz system.

The rest of the world uses 220/440V 50-60Khz, unless the country (Cuba, Costa Rica etc.) was industrialized by the Americans.

110-125V
Basic household appliances and lighting in North America.
208V Three phase (industrial, commercial) power for heating, dryers, motors etc. in North America.
220-240V Household power for heaters, motors, large loads in North America. Basic power for household appliances and lighting outside in Europe and Asia.
347V Three phase (industrial, commercial) power for lighting and motors.
440V Household power for heating, motors, large loads outside North America.
480V Early Delta system commercial/industrial power in North America.
600V Three phase (industrial, commercial) power for heating, large motors, chargers. The most efficient but the most dangerous type of power available available for use.

Three phase power is 1.73 times more efficient than single phase power. Three phase is not available for household use, too dangerous.