North American Voltage Ranges

In the US and Canada, 220, 230, 240 and 250 volts are used interchangeably to describe one voltage range that is used to power larger appliances. Similarly, 110, 115, 120 and 125 volts all refer to the one voltage range that is available through the common electrical outlet. The sources of these seemingly different numbers are as follows:

When one takes into account that equipment is designed to accept voltage variations of 10% at a minimum and that the electric utility regularly delivers electricity within 5% of their standard, there is a good match between the voltage the electric utility delivers and the voltage equipment was designed to use.