How many types of AC Voltages or commercial standards of electricity are there? Did you know that the plug used by your microwave, computer or cellphone is not the same in every country in the world? In this short post, let's take a look at the different standards in the world for voltage, frequency and plugs with their origins.
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History of AC Voltages
Let's start with history and a brief summary. How did commercial electricity come about? There was a period in history known as the War of the Currents that took place at the end of the 19th century between Thomas Edison and J.P. Morgan who advocated direct current. On the other hand, Nikola Tesla and George Westinghouse defended alternating current. Both systems had their advantages and disadvantages, but most importantly in 1893, Westinghouse Electric was commissioned to light the Chicago Fair with alternating current and later the electrical operation of Niagara Falls. It was then decided that the alternating current system at 110V with 60Hz would be the commercial standard in the United States of America.
But then the idea of generating electric current using the alternating current system was taken to each country and each nation, either because of lack of communication or because of this lack of standards, they did not agree to have a single type or standard of electric current. Each would choose a different frequency, voltage and connector but similar to their neighbors. We will see below the different types that exist in addition to some types of connectors. Each one decided the standard they thought was appropriate for their country and therefore they were not interested in creating a single common standard.
How many AC voltages and frequencies are there?
Alternating electricity is mainly composed of two characteristics: one is voltage and the other is frequency. Here is a map to help you see it clearer.
Voltages
Voltage (V) indicates the strength, tension or potential difference that exists between the two wires that reach the connector of your house. One of these is called the neutral and the other is called the line or phase. In the United States of America it was chosen to have 110V so that it could work with the incandescent bulbs that Thomas Edison had already produced and therefore it was decided that it was going to be made the standard for residential areas.
However, in Europe they decided that transporting electricity to residential areas at 220V would be more economical due to the reduction of electricity losses. So, the first big difference in AC voltages was born. Countries such as the United States, Canada, Mexico, Ecuador, Japan, Taiwan, Colombia, Venezuela, among others, use 110V nominally. This value varies between 100 and 127V in reality. Now, in most of the world 220V is used as for example most countries in Africa, in South America from Peru to Argentina, all Europe and most of Asia and Oceania.
Frequency
The next characteristic is frequency. Alternating electricity is characterized by going back and forth a certain amount of times per second. This is called Hertz (Hz). In the late 19th century, around 1890 or so, Nikola Tesla had decided that it would be appropriate to transport electricity at 60 Hertz. If the frequency was less, then light bulbs were going to flicker. If there was too much frequency, then too little electricity would pass through the wire and the transformers would run less efficiently. Today 60Hz is used from Canada to Peru in America and also in other countries such as the Philippines, South Korea and parts of Japan. On the European continent it was decided that 60 Hertz was not appropriate and it was lowered to 50 Hertz. There are many reasons, valid and simply arbitrary, but the important thing is that 50 Hertz is used in most of the planet, all of Europe, in America from Bolivia to Argentina, most of Asia, Africaand Oceania uses 50 Hertz.
Common Standards
So we have voltage and we have frequency forming a table of 4 boxes. On one axis, there are the voltages (110V and 220V) and on the other axis there are the frequencies (50Hz and 60Hz). Most of the world uses 2 standards of AC Voltages: 110V at 60Hz or 220V at 50Hz. The remaining 2 standards are used in few countries like Japan that uses 110V and 50 Hertz or countries like Philippines, South Korea or Peru that use 220V and 60Hertz.
| 110V | 220V | |
|---|---|---|
| 50Hz | 110V at 50Hz | 220V at 50Hz |
| 60Hz | 110V at 60Hz | 220V at 60Hz |
Uncommon Standards
Oh, I missed one more category of countries that have more than one electrical distribution system such as Brazil, Morocco, Saudi Arabia, Libya and Japan. The latter has 50Hz in one part of the country and 60Hz in another. In short, we have an amalgam of electrical systems with different voltages and frequencies to consider in order to use and protect our electrical and electronic devices.
But now we have to come to another complication: How do you physically or mechanically connect the device you want to power with the wall that has the residential voltage?
Power plugs, sockets and outlets for AC Voltages. How many are there?
If you already find it complicated to understand the system of various voltages with different frequencies, connectors and outlets are also a headache. At the beginning of the 20th century, there was no safe method of connecting electrical appliances, you simply had to pinch the wires with a paper clip to energize them. Soon connectors were invented to avoid the danger or pain of touching uninsulated wires. This could have been a total blessing but countries did not agree to set a single standard but each one set its own standard as it saw fit and sadly, it continues to this day.
Briefly, I will now discuss the types of connectors available. The connectors classified by country are named from the letter A to the letter N. Each one is standardized by an institution or standardization entity corresponding to each country.
For example, type A or B, is regulated by NEMA which stands for National Electrical Manufacturers Association which is established in the United States. We have type C which is commonly found in Europe. But the Europeans did not agree with the ground standard (usually the third different prong on a plug) and also developed their own connector. The French and Danish connectors are different from the Spanish, German and Russian ones (called “Schuko”) and in turn different from the British ones. This means only problems. The rest of the standards you will find in different countries like Israel, Australia, Argentina, India, etc.
Is your device compatible with different AC Voltages?
Since virtually every country has a standard, you have to find out what electrical system they use before you travel. And how exactly do we find out if our home appliance, cell phone or computer will be compatible with the country we want to visit? Good thing you asked, because I'm here to help.
Next to the charger plug of your cell phone or camera, you have to look for the voltages accepted by that device. In most cases, they will have a label indicating 100-240V 50-60Hz. This is good news! It means that your devices are compatible with ALL residential electrical systems in the world. It means that your device will no longer burn out or operate at lower power or performance. This is thanks to a switched transformer.
What if the voltage is different?
What should we do if your electric griller says 220V, 230V or 240V, but the outlet has 110V? Of course, since they are different AC Voltages, you need to buy a single-phase transformer from 110V to 220V or vice versa (they are perfectly reversible). Plug the electric griller into the connector that indicates 220V and the outlet to 110V and it will work just fine. Make sure that the transformer has a power rating higher than the wattage or watts with the letter ‘W' on the electric griller. Transformers are heavy, so don't even think about carrying them in your suitcase.
Some devices such as household appliances, microwave ovens, rice cookers, water cookers, coffee makers and so on, are usually designed for the country where they are sold. These generally do not transform electricity and use directly the mains voltage. They also make them more vulnerable, but we'll leave that for another day.
What if the frequency is different?
This is generally only a problem for AC motors. I don't think you're carrying a lot of motors on your travels are you? Hair dryers or shavers usually work fine with different frequencies. If it is a poor quality appliance or if you are not sure, consider buying the equivalent in your country of visit.
What if the connector is different?
This is the easiest and least risky part. In most electronics stores, cell phone stores, appliance stores, airports, hardware stores and so on, you will find adapters. For example, if you have an appliance with a US type B plug and you want to connect it to the European type F or type E outlet, just buy an adapter which is a piece of plastic and metal that mechanically accommodates both systems: the US plug with the European outlet. Don't forget to check if the voltage and frequency are compatible with your electrical appliance.
Now comes the million dollar question:
Is it better to buy them before traveling or when you have already arrived in your destination country?
There is no wrong answer. If you are completely sure about the adapter you will find in your host country, then you can buy it now if it is available in your home country. If you are not completely sure, wait until you arrive in the country and you can buy it. Don't worry, there are many retailers for tourists.
Some universal standards
And well, it has been an interesting post with a bit of frustration. Don't worry, I don't quite understand why we don't all agree on a single voltage standard, a single frequency standard, and a single residential plug and socket standard. This is practically a political decision and there is not much to do about it if you are an ordinary civilian.
There is one piece of good news though. There are universal electrical standards and that means you can find them in every country you visit. The first is the 12V that you find in vehicles, most have the cigarette lighter or just the battery and it works very well for different applications other than smoking.
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Apart from that, there are the USB-A and USB-C chargers (also known as USB type A and C respectively) the latter are newer. USB chargers provide 5 V DC current and are popular for cell phone charging, but they also power other low power electrical and electronic devices. For example, battery chargers, computer or cell phone mice, etc etc etc. USB-C chargers allow higher power up to 100 W and can be connected to various voltage standards such as 5, 9, 12, 15 and 20 volts DC when it has the ‘PD' feature which stands for “Power Delivery”. The best part of it all is that you as a user do not have to manually choose and verify specifically the voltage your device will use, but on the contrary: the device itself communicates with the charger and decides how much voltage it will use. Wow, how convenient!
With this standard it can be said that we have indeed reached a universal standard of power transmission. I am really very grateful and let's just say that my faith in humanity has been restored.
Conclusions of the differents AC Voltages
So, what did you think of this lesson on electricity and how to be careful when visiting a different country? What is the voltage in your country? Have you ever burned something important because you didn't know the voltage?
If you are interesting to traveling and advice about what to do and how to do safely, check out the sister page of techZorro, focused on experiences, cultures, travels and languages. It's called voyageLlama and you can find it here:
External Links
- Teslapedia. Turner Publicaciones 2014. Link.
- USB Type-C, Power Delivery and Programmable Power Supply. Cui Inc. Link.
- USB-C. Wikipedia. Link.
- Mains electricity. Wikipedia. Link.
- Mains electricity by country. Wikipedia. Link.
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