三相电-Three-phase electric power (industrial applications only)

Although single-phase power is more prevalent today, three-phase is still chosen as the power of choice for many different types of applications. Generators at power stations supply three-phase electricity. This is a way of supplying three times as much electricity along three wires as can be supplied through two, without having to increase the thickness of the wires. It is usually used in industry to drive motors and other devices.

Three-phase electricity is by its very nature a much smoother form of electricity than single-phase or two-phase power. It is this more consistent electrical power that allows machines to run more efficiently and last many years longer than their relative machines running on the other phases. Some applications are able to work with three-phase power in ways that would not work on single phase at all.

Mind you, since three-phase electricity is rarely used for domestic purposes, the table below is only relevant to electricians, electrical engineers and other technically skilled people. Travellers and laymen should take a look at the single-phase voltage table.

Country	Three-phase voltage (volts)	Frequency (hertz)	Number of wires (not including the ground wire)
Abu Dhabi (not a country, but capital of the United Arab Emirates)	400 V	50 Hz	3, 4
Afghanistan	380 V	50 Hz	4
Albania	400 V	50 Hz	4
Algeria	400 V	50 Hz	4
American Samoa	208 V	60 Hz	3, 4
Andorra	400 V	50 Hz	3, 4
Angola	380 V	50 Hz	4
Anguilla	120/208 V / 127/220 V / 240/415 V	60 Hz	3, 4
Antigua and Barbuda	400 V	60 Hz	3, 4
Argentina	380 V	50 Hz	3, 4
Armenia	400 V	50 Hz	4
Aruba	220 V	60 Hz	3, 4
Australia	400 V	50 Hz	3, 4
Austria	400 V	50 Hz	3, 4
Azerbaijan	380 V	50 Hz	4
Azores	400 V	50 Hz	3, 4
Bahamas	208 V	60 Hz	3, 4
Bahrain	400 V	50 Hz	3, 4
Balearic Islands	400 V	50 Hz	3, 4
Bangladesh	380 V	50 Hz	3, 4
Barbados	200 V	50 Hz	3, 4
Belarus	380 V	50 Hz	4
Belgium	400 V	50 Hz	3, 4
Belize	190 V / 380 V	60 Hz	3, 4
Benin	380 V	50 Hz	4
Bermuda	208 V	60 Hz	3, 4
Bhutan	400 V	50 Hz	4
Bolivia	400 V	50 Hz	4
Bonaire	220 V	50 Hz	3, 4
Bosnia & Herzegovina	400 V	50 Hz	4
Botswana	400 V	50 Hz	4
Brazil	220/380 V	60 Hz	3, 4
British Virgin Islands	190 V	60 Hz	3, 4
Brunei	415 V	50 Hz	4
Bulgaria	400 V	50 Hz	4
Burkina Faso	380 V	50 Hz	4
Burma (officially Myanmar)	400 V	50 Hz	4
Burundi	380 V	50 Hz	4
Cambodia	400 V	50 Hz	4
Cameroon	380 V	50 Hz	4
Canada	120/208 V / 240 V / 480 V / 347/600 V	60 Hz	3, 4
Canary Islands	400 V	50 Hz	3, 4
Cape Verde (in Portuguese: Cabo Verde)	400 V	50 Hz	3, 4
Cayman Islands	240 V	60 Hz	3
Central African Republic	380 V	50 Hz	4
Chad	380 V	50 Hz	4
Channel Islands (Guernsey & Jersey)	400 V	50 Hz	4
Chile	380 V	50 Hz	3, 4
China, People’s Republic of	380 V	50 Hz	3, 4
Colombia	220 V / 440 V	60 Hz	3, 4
Comoros	380 V	50 Hz	4
Congo, Democratic Republic of the (Congo-Kinshasa)	380 V	50 Hz	3, 4
Congo, Republic of the (Congo-Brazzaville)	400 V	50 Hz	3, 4
Cook Islands	415 V	50 Hz	3, 4
Costa Rica	240 V	60 Hz	3, 4
Côte d’Ivoire (Ivory Coast)	380 V	50 Hz	3, 4
Croatia	400 V	50 Hz	4
Cuba	190 V / 440 V	60 Hz	3
Curaçao	220 V / 380 V	50 Hz	3, 4
Cyprus	400 V	50 Hz	4
Czechia (Czech Republic)	400 V	50 Hz	3, 4
Denmark	400 V	50 Hz	3, 4
Djibouti	380 V	50 Hz	4
Dominica	400 V	50 Hz	4
Dominican Republic	120/208 V / 277/480 V	60 Hz	3, 4
Dubai (not a country, but the largest city in the United Arab Emirates)	400 V	50 Hz	3, 4
East Timor (Timor-Leste)	380 V	50 Hz	4
Ecuador	208 V	60 Hz	3, 4
Egypt	380 V	50 Hz	3, 4
El Salvador	200 V	60 Hz	3
England	400 V	50 Hz	4
Equatorial Guinea	[unavailable]	[unavailable]	[unavailable]
Eritrea	400 V	50 Hz	4
Estonia	400 V	50 Hz	4
Ethiopia	380 V	50 Hz	4
Faeroe Islands	400 V	50 Hz	3, 4
Falkland Islands	415 V	50 Hz	4
Fiji	415 V	50 Hz	3, 4
Finland	400 V	50 Hz	3, 4
France	400 V	50 Hz	4
French Guiana	380 V	50 Hz	3, 4
Gabon (Gabonese Republic)	380 V	50 Hz	4
Gambia	400 V	50 Hz	4
Gaza	400 V	50 Hz	4
Georgia	380 V	50 Hz	4
Germany	400 V	50 Hz	4
Ghana	400 V	50 Hz	3, 4
Gibraltar	400 V	50 Hz	4
Great Britain (GB)	400 V	50 Hz	4
Greece	400 V	50 Hz	4
Greenland	400 V	50 Hz	3, 4
Grenada	400 V	50 Hz	4
Guadeloupe	400 V	50 Hz	3, 4
Guam	190 V	60 Hz	3, 4
Guatemala	208 V	60 Hz	3, 4
Guinea	380 V	50 Hz	3, 4
Guinea-Bissau	380 V	50 Hz	3, 4
Guyana	190 V	60 Hz	3, 4
Haiti	190 V	60 Hz	3, 4
Holland (officially the Netherlands)	400 V	50 Hz	3, 4
Honduras	208 V / 230 V / 240 V / 460 V / 480 V	60 Hz	3, 4
Hong Kong	380 V	50 Hz	3, 4
Hungary	400 V	50 Hz	3, 4
Iceland	400 V	50 Hz	3, 4
India	400 V	50 Hz	4
Indonesia	400 V	50 Hz	4
Iran	400 V	50 Hz	3, 4
Iraq	400 V	50 Hz	4
Ireland, Republic of (Eire)	400 V	50 Hz	4
Ireland, Northern	400 V	50 Hz	4
Isle of Man	400 V	50 Hz	4
Israel	400 V	50 Hz	4
Italy	400 V	50 Hz	4
Jamaica	190 V	50 Hz	3, 4
Japan	200 V	50 Hz / 60 Hz	3
Jordan	400 V	50 Hz	3, 4
Kazakhstan	380 V	50 Hz	3, 4
Kenya	415 V	50 Hz	4
Kiribati	[unavailable]	[unavailable]	[unavailable]
Korea, North	380 V	50 Hz	3, 4
Korea, South	380 V	60 Hz	4
Kosovo	230 V / 400 V	50 Hz	3
Kuwait	415 V	50 Hz	4
Kyrgyzstan	380 V	50 Hz	3, 4
Laos	400 V	50 Hz	4
Latvia	400 V	50 Hz	4
Lebanon	400 V	50 Hz	4
Lesotho	380 V	50 Hz	4
Liberia	208 V	60 Hz	3, 4
Libya	400 V	50 Hz	4
Liechtenstein	400 V	50 Hz	4
Lithuania	400 V	50 Hz	4
Luxembourg	400 V	50 Hz	4
Macau	380 V	50 Hz	3
Macedonia, North	400 V	50 Hz	4
Madagascar	380 V	50 Hz	3, 4
Madeira	400 V	50 Hz	3, 4
Malawi	400 V	50 Hz	3, 4
Malaysia	415 V	50 Hz	4
Maldives	400 V	50 Hz	4
Mali	380 V	50 Hz	3, 4
Malta	400 V	50 Hz	4
Marshall Islands	[unavailable]	[unavailable]	[unavailable]
Martinique	380 V	50 Hz	3, 4
Mauritania	380 V	50 Hz	3, 4
Mauritius	400 V	50 Hz	4
Mayotte	[unavailable]	[unavailable]	[unavailable]
Mexico	220 V / 480 V	60 Hz	3, 4
Micronesia, Federated States of	[unavailable]	[unavailable]	[unavailable]
Moldova	400 V	50 Hz	4
Monaco	400 V	50 Hz	4
Mongolia	400 V	50 Hz	4
Montenegro	400 V	50 Hz	3, 4
Montserrat	400 V	60 Hz	4
Morocco	380 V	50 Hz	4
Mozambique	380 V	50 Hz	4
Myanmar (formerly Burma)	400 V	50 Hz	4
Namibia	380 V	50 Hz	4
Nauru	415 V	50 Hz	4
Nepal	400 V	50 Hz	4
Netherlands	400 V	50 Hz	3, 4
New Caledonia	380 V	50 Hz	3, 4
New Zealand	400 V	50 Hz	3, 4
Nicaragua	208 V	60 Hz	3, 4
Niger	380 V	50 Hz	4
Nigeria	415 V	50 Hz	4
Northern Ireland	400 V	50 Hz	4
North Korea	380 V	50 Hz	3, 4
North Macedonia	400 V	50 Hz	4
Norway	230 V / 400 V	50 Hz	3, 4
Oman	415 V	50 Hz	4
Pakistan	400 V	50 Hz	3
Palau	208 V	60 Hz	3
Panama	240 V	60 Hz	3
Papua New Guinea	415 V	50 Hz	4
Paraguay	380 V	50 Hz	4
Peru	220 V	60 Hz	3
Philippines	380 V	60 Hz	3
Pitcairn Islands	[unavailable]	[unavailable]	[unavailable]
Poland	400 V	50 Hz	4
Portugal	400 V	50 Hz	3, 4
Puerto Rico	480 V	60 Hz	3, 4
Qatar	415 V	50 Hz	3, 4
Réunion	400 V	50 Hz	4
Romania	400 V	50 Hz	4
Russia (officially the Russian Federation)	380 V	50 Hz	4
Rwanda	400 V	50 Hz	4
Saba	[unavailable]	[unavailable]	[unavailable]
Saint Barthélemy (informally also referred to as Saint Barth’s or Saint Barts)	[unavailable]	[unavailable]	[unavailable]
Saint Kitts and Nevis (officially the Federation of Saint Christopher and Nevis)	400 V	60 Hz	4
Saint Lucia	400 V	50 Hz	4
Saint Martin	[unavailable]	[unavailable]	[unavailable]
Saint Helena	[unavailable]	[unavailable]	[unavailable]
Sint Eustatius	220 V	60 Hz	3, 4
Sint Maarten	220 V	60 Hz	3, 4
Saint Vincent and the Grenadines	400 V	50 Hz	4
Samoa	400 V	50 Hz	3, 4
San Marino	400 V	50 Hz	4
São Tomé and Príncipe	400 V	50 Hz	3, 4
Saudi Arabia	400 V	60 Hz	4
Scotland	400 V	50 Hz	4
Senegal	400 V	50 Hz	3, 4
Serbia	400 V	50 Hz	3, 4
Seychelles	240 V	50 Hz	3
Sierra Leone	400 V	50 Hz	4
Singapore	400 V	50 Hz	4
Slovakia	400 V	50 Hz	4
Slovenia	400 V	50 Hz	3, 4
Solomon Islands	[unavailable]	[unavailable]	[unavailable]
Somalia	380 V	50 Hz	3, 4
Somaliland (unrecognised, self-declared state)	380 V	50 Hz	3, 4
South Africa	400 V	50 Hz	3, 4
South Korea	380 V	60 Hz	4
South Sudan	400 V	50 Hz	4
Spain	400 V	50 Hz	3, 4
Sri Lanka	400 V	50 Hz	4
Sudan	400 V	50 Hz	4
Suriname	220 V / 400 V	60 Hz	3, 4
Swaziland	400 V	50 Hz	4
Sweden	400 V	50 Hz	3, 4
Switzerland	400 V	50 Hz	3, 4
Syria	380 V	50 Hz	3
Tahiti	380 V	50 Hz / 60 Hz	3, 4
Taiwan	220 V	60 Hz	4
Tajikistan	380 V	50 Hz	3
Tanzania	415 V	50 Hz	3, 4
Thailand	400 V	50 Hz	3, 4
Togo	380 V	50 Hz	4
Tonga	415 V	50 Hz	3, 4
Trinidad & Tobago	115/230 V / 230/400 V	60 Hz	4
Tunisia	400 V	50 Hz	4
Turkey	400 V	50 Hz	3, 4
Turkmenistan	380 V	50 Hz	3
Turks and Caicos Islands	240 V	60 Hz	4
Uganda	415 V	50 Hz	4
Ukraine	400 V	50 Hz	4
United Arab Emirates (UAE)	400 V	50 Hz	3, 4
United Kingdom (UK)	400 V	50 Hz	4
United States of America (USA)	120/208 V / 277/480 V / 120/240 V / 240 V / 480 V	60 Hz	3, 4
United States Virgin Islands	190 V	60 Hz	3, 4
Uruguay	380 V	50 Hz	3
Uzbekistan	380 V	50 Hz	4
Vanuatu	400 V	50 Hz	3, 4
Venezuela	120 V	60 Hz	3, 4
Vietnam	380 V	50 Hz	4
Virgin Islands (British)	190 V	60 Hz	3, 4
Virgin Islands (USA)	190 V	60 Hz	3, 4
Wales	400 V	50 Hz	4
Yemen	400 V	50 Hz	4
Zambia	400 V	50 Hz	4
Zimbabwe	415 V	50 Hz	3, 4