Housing in Japan - Utilities - Electricity

Electricity

Most Japanese dwellings are connected to the nation's power grid by using 3-wire system with standard phase-neutral voltage of 100 V. 100 V AC outlets are located throughout the home for general use. Few 200 V outlets may also exist for connecting induction heating stove or large air conditioner. The line frequency is 50 Hz in eastern Japan, and 60 Hz in the western part of the country. Service limiters of 30 to 60 A is typical for some electricity distributors.

Many domestic appliances operate properly at either frequency. Outlets resemble those formerly used in the North America (see comparison), with two vertical slots. The older outlets are unpolarized and many sockets lack earthing capability. Outlets in the kitchen, toilet, and bathroom, as well as those supplied by the ceiling for air-conditioning units do usually have earthing, either in the form of an 3-pin outlet or a covered binding post. Devices designed for use with water, such as clothes washers and heated toilet seats, often have a separate earth wire or earth pin. Cheater plug adapters are readily available to convert such plugs and so allow their use in all types of sockets.

Since 2005, new Japanese homes are required to have 3-pin earthed outlets for connecting domestic appliances. This rule does not apply for the outlets not intended to be used for domestic appliances, but it is strongly advised to have 3-pin outlets throughout the home.

• 100V polarized outlet (JIS C 8303; 15A125V)

• 3-pin earthed outlet (JIS C 8303 15A125V)

• 3-pin high ampacity outlet, typically used for air conditioners (JIS C 8303; 20A125V)

• 200V earthed outlet, typically used for stoves and larger air conditioners (JIS C 8303; 20A250V)