One of the two world standards for AC current is the 120-volt, 60-cycle current developed in the United States and used in most of the Western Hemisphere. Although 120 volts is nominal, actual supplied voltage in any given country varies between 100 and 127 volts. Besides the United States, the 120/60 standard is used in Canada, Mexico, Central America, most of the Caribbean islands, the northern half of South America, Liberia, Saudi Arabia, Surinam, both Koreas, Taiwan, Micronesia and the southern half of Japan.
The other world AC standard is the 230-volt, 50-cycle current developed in Germany. Although 230 volts is nominal, actual supplied voltage in any given country varies between 220 and 240 volts. This 230/50 standard applies throughout Western and Eastern Europe, Russia, Africa and the entire Eastern Hemisphere except for Liberia, Japan, both Koreas, Micronesia, and Madagascar. Western Hemisphere nations on this standard include Iceland, Greenland, Argentina, Chile and French Guyana.
Some nations don't adhere to either the U.S. or European current standards. Northern Japan and Madagascar use 120 volts but at 50 cycles. Guyana runs 240 volts at 60 cycles. Montserrat, Antigua and the Leeward Islands use 230 volts but at 60 cycles. The Philippines and Peru use 220 volts at 60 cycles. Fortunately, most electrical equipment can tolerate some departure from the nominal standard for which it was designed, so you can use normal 120- or 230-volt devices in these countries.
Electrical and electronic products designed for the 120-volt standard will burn out if plugged directly into a 230-volt outlet. Products designed for the 230-volt standard will either run sluggishly or not work at all on 120-volt current. Some devices are designed to work with both power standards, so all you need is a plug adapter to fit the outlets where you are. For equipment that works with only one of the standards, devices are available that reduce 230 volts to 120 volts or step 120 volts up to 230 volts. Most electrical devices will work on either 50- or 60-cycle current, but clocks and other timing devices meant for one AC cycle standard won't keep accurate time if run on the other standard.
