Electrical outlets differ according to the country and whether the outlet is for consumer or industrial use. When traveling, knowledge about outlets, voltage, current and power as well as common safety features can prevent a blown fuse, fire, electrocution, or damage to your equipment.
The American electrical system is based on a 120-volt system, though most of the rest of the world functions at 220 volts. Specialized industrial and medical outlet subtypes are uninterrupted or allow higher voltages.
Power and Current
The amount of current (amps) multiplied by the voltage equals the power (watts) used by the appliance. A fuse will blow if the current (amps) required exceeds that of the fuse in the circuit, such as when a toaster oven and microwave are run simultaneously on the same circuit.
Grounded outlets allow a path for electricity to flow into the ground instead of through your body. A GFCI (ground fault circuit interrupter) prevents electrocutions by sensing when electricity is running to ground and shutting off the circuit. Bathroom outlets have GFCI to shut off power if the hairdryer is dropped into the bathtub.
Travel adapters allow you to plug an appliance with one type of plug into an outlet with a different structure. They do not convert the electricity that comes out of the outlet. Consult a table online to determine the voltage and frequency delivered in the country you will visit. A transformer with the correct wattage rating (built-in to most computers) reduces the voltage coming out of the outlet to prevent damaging your appliance.
Outlets are classified into types A through M. In the U.S. and Japan, the A type is an ungrounded outlet with two prongs, Type B has unequal prong heights, the middle prong is inserted first and grounds the device before it becomes live.
United Kingdom Standard
The U.K. and Ireland use the type G outlet with three straight prongs. The type D outlet used in India and Pakistan. Type M (South Africa) is similar to the British type G outlet except it has three rounded prongs.
Europe and Elsewhere
The most common plug in the world is the Type C Euro plug, an ungrounded two-prong rounded plug designed for the type C outlet which looks just like the Type F Schuko plug but has no ground on the side. The Type C Euro Plug fits into outlet types E, F, H, L, or K.
The French type E outlet has a male ground prong in the outlet which fits into a female plug hole.
In Switzerland (Type J), Italy (Type L) and Denmark (Type K), a central grounding pin on the plug was added to the C type Euro Plug.
Israel has its own outlet, the Type H, which is like the U.S. type B except its prongs are angled like a V. It was modified in 1989 to have round prongs to accept the type C plug.
The Australian and Chinese Type I grounded V-shaped plug looks similar to the Israeli type H, but they are not compatible.