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Electrical systems

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Electrical systems

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Universal Plug Adaptor

    This article is a travel topic

Electrical systems differ around the world. Some use 50 hertz; some 60. Some use 110-120 volts; others 220-240. Some are on all the time, barring an ice storm or earthquake; some run a few hours a day. The plugs are also different so travelers with electrical appliances should ensure that they are adequately prepared.


Voltage and frequency

Map of the world coloured by voltage and frequency

Start by taking a look at the back of the device you want to use. If if says "100-240V, 50/60 Hz" or something similar, it will work anywhere in the world, and you can skip right to the next section. If it doesn't, keep reading.

Dealing with electricity differences can be daunting, but it actually isn't too hard. There are only two main type of electric systems used around the world, with varying physical connections:

  • 110-120 volt, at 60 hertz frequency (in general: North and Central Americas, Western Japan)
  • 220-240 volt, at 50 hertz frequency (in general: the rest of the world, with some exceptions)

Occasionally, you will find 110-120 volts @ 50 Hz such as in Tokyo, Japan; and conversely, 220-240 volts @ 60 Hz such as in Manila, the Philippines. Such systems are not common worldwide, though.

If the voltage and frequency for your device is the same as where you are travelling, then you need only worry about the physical plug. (The small difference between 110V and 120V, or between 220V and 240V is within the tolerances of most electrical devices.)

If the voltage for your device is not the same, then you will need a transformer to convert the voltage. Transformers are basically chunks of iron specially-wrapped in wires, which means that they are large and heavy. To use one, you must verify that the voltage is being stepped up (low to high voltage) or stepped down (high to low voltage) in the right direction: plugging a 110-to-220V step-up transformer into a 220V socket will get you 440V and a fried device. You must also make sure that the wattage of your device does not exceed the transformer's limit, as doing so may cause the transformer to overheat and even catch fire.

To convert 240V to 120V, lighter weight "switching" converters are available and can handle larger wattage loads up to 1600 watts. Note that they can only step down voltage, not raise it. The electric waveform they produce is not compatible with digital electronics, so it can't be used to power appliances using any such parts. (And always use high quality surge protection with sensitive electronic equipment.)

If the frequency is not the same, there is really nothing you can do about that. Unlike voltage, frequency cannot easily be converted. (Foreign embassies may have to use huge generators to provide current compatible with equipment from home.) But most travel items will work OK on either 50 or 60 Hz. If all the electrical appliance does is produce heat and/or light, then the frequency doesn't matter. On the other hand, appliances that are motorized without the option of batteries, or display the time are dependent on the frequency to work correctly. Some travel items containing an electric motor such as a hairdryer might say 50/60 Hz on the label, which means it will work on either frequency.

In general, any device that can run on batteries, but also has an electric cord to save the batteries for when they are needed can usually be operated from either 50 or 60 Hz (but the voltage must match or be converted). Be cautious, though, with anything extra sensitive and/or expensive as the design of power supplies where the AC is converted into DC (i.e. battery-like current) does take frequency into account. 60Hz converts a little more easily to DC than 50 Hz does, but there's enough tolerance in most small appliances and electronic gadgets that this can be ignored. As noted above, you cannot use a switching-type converter in this situation. It must be the heavier iron-core transformer if the power mains voltage is different and you want to convert AC to DC (to save or charge batteries).

Plugs and adapters

Plug types
Map of the world coloured by type of plug used

A device that lets you insert a plug into a different socket is an adapter: these are small, cheap, safe and pretty much unbreakable. For example, between England and Germany, you need only an adapter. You stick your British plug in the adapter, which connects the rectangular phase and neutral prongs to the round German ones and puts the ground where the German outlet expects it, and you're good to go.

Unfortunately, there are lots of different plugs in the world. The three big standards are:

  • The "American" (Type A) plug, with two vertical pins
  • The "European" (Type C) plug, with two round pins
  • The "British" (Type G) plug, with three rectangular pins

If your device has one of these plugs and you can adapt it to the others, you've got 90% of the world covered. (The main exceptions are South Africa, Australia, New Zealand, Argentina and parts of China, which use a Type I plug with two slanted pins.) Adapters between Type A and Type C and from C to G are tiny and cheap; converting Type A into G or Type G into anything else, on the other hand, needs a bulkier model.

For hobbyists: if you can't find an adapter, and you're staying for a longer time, just buy a separate plug at your destination, remove the existing plug and attach the new one. Plugs are always available, unlike adapters. They're cheaper too. Caution: only try this if you know what you're doing!

As a last resort, a Type C plug can be forced into a Type G socket without any converter at all if you ignore what your mother told you and stick a pen or similar pointy object into the center (ground) hole, which fools the socket into thinking a ground pin has been inserted and opens up the other holes. Disable power to the socket and try to use something non-conductive to do this!

There's one more complication to consider: any two-pin socket is ungrounded, while all three-pin plugs are grounded. Trying to get grounding to work makes life more difficult, as any of sockets C, D, E, F, J or L will happily accept the ungrounded plug C, but will not work with any grounded variant other than their own. It's thus very tempting to use an adapter to turn a three-pin into a two-pin, but this will disable grounding, potentially leaving the device (and you) vulnerable to short circuits and other electrical nastiness.

A last word of warning: many developing countries use multi-plug sockets that accept (say) both Type A and Type C. Don't assume the voltage is correct just because the plug fits, since a Thai Type A+C socket still carries 220V and will thus fry unsuspecting American (110V) Type A devices to a crisp.

Unstable supply

In many developing countries, electrical supply is highly erratic and you need to take precautions to protect your equipment.

The main danger is power spikes, where the amount of power supplied temporarily surges to dangerous levels, with potentially catastrophic consequences. In developed countries, the main source of spikes is lightning strikes, but in developing countries they're most often associated with power outages since when the power comes back on, it rarely does so smoothly. The cheapest method of protection is thus simply to disconnect electronic devices as soon as the power goes out, and wait a few minutes after the power comes back on until plugging them back in.

Surge protectors are devices designed specially to protect against spikes and surges, and some are available in portable travel-sized versions. Some surge protectors can also be fitted to a telephone line to protect your phone or laptop modem. The most common variety use a metal oxide varistor (MOV), which shorts to ground if a given voltage is exceeded. These are easily destroyed by larger spikes, and better models will have a light indicating when the MOV has broken down, but you still need to keep an eye on them as the device will still continue to give power even if the protection is gone. There are also surge protectors with fuses, which are fail-safe (a blown fuse will stop power) and replaceable, but they are also riskier as a short, sharp spike can pass through and damage your device before the fuse blows.

In some (mostly poor) regions, you may experience electricity voltage drops. Instead of 240V for example, you may only get 200V or even less. This happens especially if you're at "the end of the line" (far from the source or transformer) and is caused by the resistance of the electric lines themselves. Some appliances, such as light bulbs and heating equipment just keep working under a lower voltage, although a 20% voltage drop will cause a 36% power drop. Most electronic devices also keep working, but voltage drops are critical for fluorescent lamps and refrigerators, which may stop working altogether (usually without being damaged, when the voltage returns to normal, they will start working again).

Voltage drops can be solved with a special device called a voltage stabiliser. A stabiliser will raise the voltage again to its normal level. The principle is the same as for switching converters, except that stabilisers will produce a stable output, even with an unstable input. Stabilisers come in different power ranges, but they're all large, bulky and not practical to carry around. Be aware that some appliances, such as refrigerators, briefly consume twice or 3 times more power at start-up; the stabiliser should be able to provide this power.


Laptop computers

Virtually all laptop computers (including those with internal power supplies) will handle either 220 or 120 volts fine, however you will need to make sure that you have the plug that matches the outlet for the country you are going to.


Radios also tend to be interchangeable from country to country. The exact FM range being used can vary from country to country though, so you may not be able to access all stations. In the US, only odd channels (88.1,88.3, 100.1 etc) are used. A radio intended for the US market will not work correctly in most other countries. Japan, in particular, has an FM band from 76 MHz to 90 MHz rather than the more common 87.5 MHz to 108 MHz. The countries of the former Soviet Union also use a similar band. For the medium wave band, channel spacings (the difference between each valid frequency) can be 9kHz or 10kHz (for USA). Some digital radios will have a switch or setting to choose which channel spacing is used. Without this they will not work correctly outside their intended market. Old-fashioned analog-dial tuners don't have this limitation.

Mobile phones and digital cameras

Chargers for these may work with both 110V and 240V systems, though you may still need an adaptor plug or have to use the shaver socket. You may be able to get a second charger for the other voltage system, or even a dual voltage charger designed for both systems. However, your mobile phone handset may not be compatible with the country's network, or you may be limited to certain cellular providers. (See Telephone service for travel#Cell phones.)

Equipment using standard batteries

Battery sizes and voltages tend to be standard from place to place, and equipment that uses off-the-shelf batteries tends to be interchangable.

Be cautious with:


In many countries without fully developed electrical power distribution systems, the use of generators is common. Generator supplies can be very good, however, in many places they are not and can cause damage to sensitive equipment if it is connected. The voltage, frequency and waveform shape (it should be a smooth sine-wave) can vary. In some places people modify generators to run faster. This gives more voltage and power but increases the frequency too. The part of a generator that keeps it running at a constant speed is called the governor. If this is tampered with, the output voltage could rise sufficiently to cause damage. The best advice is not to connect valuable equipment to the supply or at the very least disconnect it as soon as it is finished with.

If you are unsure about the quality of generator in use, there are a few simple rules. If it runs from petrol/gasoline it is bad - anyone serious about using generator power uses a diesel oil powered system. A good quality generator will have a low engine speed. 1500RPM for 50Hz or 1800RPM for 60Hz. If the engine speed is 3000RPM+, it is not a good machine.


Lamps and their light bulbs are very sensitive to voltage. If you shift between voltage systems, you will need to change the light bulbs to match the voltage, unless the lamp is designed to operate on both systems, say through a low voltage adaptor. If you buy a lamp abroad, you may need to have an electrician completely rewire a lamp when you get home to comply with your country's electrical safety standards. This may not be a problem for a one off special item, but if you are going into the importing business it could be a showstopper.

Also watch out for the light bulb connection. In 110-120V systems this is often a screw connector while in 220-240V systems it is often a bayonet connector. These connectors also come in at least two different sizes. Be sure you can obtain light bulbs of the right voltage, size and connector shape in the country you intend to use the lamp, and at a reasonable price, otherwise the lamp may become little more than junk when the bulb fails.

Electric motors

The electric motors in things like refrigerators, vacuum cleaners, washing machines and other whiteware are often sensitive to frequency. Older hairdryers and electric shavers might be also. Even if you use a step-up or step-down transformer, the different supply frequencies mean motors run at the wrong speed and burn out. The larger and more powerful the motor is, the more this is true. Don't, for example, bring a vacuum cleaner from the USA to Europe (or vice versa). It's almost guaranteed to fail -- even if you have a voltage converter.

Electric Shavers

Hotels often provide a special electrical outlet specifically for electric shavers. They allow any voltage shaver to be plugged into them and be used safely in front of the bathroom mirror. They may also accept your cellphone adaptor or similar low power battery charging unit. Many – but not all – electric shavers sold today are dual voltage 50/60Hz and some will even recharge the battery at 12V DC (such as in an automobile). Check the label and instructions for compatibility.


Hairdryers are a particular risk; if you accidentally plug your 100-120 Volt hairdryer into a 240 Volt outlet you may find it catching fire in your hands! Similarly a 220-240 Volt hairdryer in a 120 Volt outlet may run slowly and not heat up enough. Most good hotels and motels will be able to supply a hair drier, it may even be a room fitting. However it may be worthwhile buying or borrowing a hairdryer suited for the electrical system of countries you may be travelling in.

Many new hairdryers sold in 100-120V countries are dual voltage with settings for 100-120V and 220-240V. Even though it's motorized, it will work on either 50 or 60 Hz. Be sure to "lock out" the high setting when it's plugged into 220-240 volts, or it will quickly burn out, or worse! (The low setting will be as powerful as the high setting was at 120V, with low speed unavailable.)


An electric clock of any sort is very sensitive to the type of current. If the voltage if doubled or halved it will not function at all and may burn out. Furthermore, the electric frequency (50 or 60 Hz) is used to keep the time, and this applies to both analogue and digital clocks. Thus, if a clock made for North America were used in Europe – even with a voltage adapter – it would lose 10 minutes per hour! Obviously, not a great idea if you have a train to catch. Conversely, a European clock would gain 12 minutes per hour in North America. The best solution is to just use a battery operated or wind-up clock.

Video equipment

Televisions, many radios, video and DVD players, as well as videotapes, are often specific to the broadcast system used in the country that they are sold in, usually associated with the frequency of the country's electric current. For example, North America is 60 Hz and its television is 30 frames per second, while Europe is 50 Hz and its television is 25 frames per second. The main three television broadcast systems are PAL, the closest to a worldwide standard, NTSC, used mostly in the Americas and some East Asian countries (notably Japan, South Korea, the Philippines and Taiwan) and SECAM, originally from France and adopted by much of Eastern Europe and the Middle East, but there are various incompatibilities even within these supposed standards. There is no difference between PAL and SECAM for unconverted DIGITAL video including DVDs. However, any analog output to a television set would be in the native format of the country of location. Brazil uses a hybrid PAL/NTSC standard called "PAL-M". In Brazil, DVDs and video tape are the same as NTSC (without region coding -- see below), but all players and TV sets are useless outside the country unless they have a separate NTSC setting.

Before purchasing any video equipment, read the manual and warranty carefully. For TVs and VCRs don't forget about cable television frequencies; they may not be the same, even if everything else is. Television sets often won't work correctly in another country from where they were sold, even if the voltage and video standard are the same. For example, a television set made for the USA will skip a few channels in Japan. Unless you have an internationally compatible device you may find your expensive looking system is little more than worthless junk in another country because it won't work with your country's broadcast system. Your warranty is probably only valid in the country of purchase, and you may need to return the goods to the place you purchased them from.

DVDs, infuriatingly, have a completely artificial limitation introduced in the form of region coding, which attempts to limits the region where the discs can be used, as a technique to keep the various regions as separate markets. For example, a Region 1 player in North America will not play a Region 3 DVD from Hong Kong. The workaround are to obtain either a regionless DVD player which ignores the code, purchase multi-region discs (regions 1 & 3 in this case), or better yet, region 0 discs that can be played on any device.

Technically, there is no such thing as a NTSC or PAL DVD disc, as all color information is the same for both. When discs are labeled as such, what they're refering to is the picture size and frame rate (i.e. number of frames per second) that are used in most (but not all!) countries that have TV broadcasts on this same system. Many NTSC players cannot play PAL DVDs, unless that's a specific feature included (many Philips and JVC models include this). PAL DVD players are generally much better at playing NTSC, but it's not a certainty. If all else fails, a computer DVD-ROM can play any DVD movie (not including HD & Blu-ray), though there's a limit on how many times you can change the region code. Unlike analouge televison sets, computer monitors can automatically handle both 25 (PAL & SECAM) and 30 (NTSC) frames per second, as well as various picture sizes. This also applies to LCD and plasma "flat panel" television sets, but don't expect their tuner to be compatible outside the country in which they were sold.

Videocameras can usually be charged with both electrical systems so you can record during travels and view it back home. Digital cameras and videocameras can usually output to both PAL, NTSC, and SECAM, so you can view your recording while travelling. Bring an RCA (yellow plug) to SCART adaptor if you plan to view video from a camcorder on a European television set.

VHS and other tape formats, while becoming out of date, still exist. There is no compatibility between NTSC and PAL. Professional conversions will probably cost most than the original. Some manufacturers, such as Philips and Samsung, make or did make several VHS VCR models that will play and record any foreign video format, though these machines are hard to find (try online and mail order) and relatively expensive. Also, you won't be able to make copies of tapes in the format that's not of your country if both the master and the needed copy(s) are of that foreign format. (Unless, of course, you're wealthy enough to afford two of these machines.) You could do a double conversion, but the quality will suffer greatly. One workaround would be to make a DVD in this foreign format, then play it back again to the multi-format VCR. You'll need a computer video capture card capable of both formats (many aren't), DVD production software reset to this foreign format, and a DVD player also capable of playing with an output (not just internal conversion!) of both formats (most aren't, except for the Philips brand) to play it back to the multi-format VCR. If you just want DVD copies, skip the last step of the DVD player playing it back to the VCR, and burn as many copies as you need.

Converting DVDs from one format to another (while retaining their quality) is not a job for amateurs. Best to pay a pro to do it. (Look in the yellow pages under Video.) From this converted disc, you can then burn as many copies as you need. Regular blank discs and software work fine for making copies of a foreign format, as it's all just a bunch of one's and zero's and no different than copying anything else. However, as noted previously, converting it and playing it on a television set is another matter.

Stay safe

The first time you use electrical equipment on a voltage system you haven't used before, watch for excessive heat, strange smells, and smoke. This especially true for those residing in countries with 120V (USA, Canada, Japan, etc.) visiting places with the higher voltage. Smoke is a sure sign your equipment cannot cope with the voltage system.

If your electrical equipment gets very hot, smells of burning (there is a distinct smell of electrically fried circuit boards) or starts to smoke, turn it off at the wall or the main switch immediately, then carefully unplug the equipment. Do not disconnect or unplug by just grabbing the smoking device, its plug or cord, and then unplugging it, as these parts are probably very hot, and the insulation could be melted or unsafe, which could result in electrocution.

Unfortunately, you may find your expensive equipment has been fried and needs to be replaced because the wrong voltage was used. However, if the equipment only got hot and did not smoke or produce strange burning smells you may be lucky.

Also, do not rely on fuses protecting your equipment. They are normally not sensitive enough, though if they do blow when you plug your equipment in, you should have things checked by a competent local electrician before using the suspect equipment again.

In third-world countries with frequent blackouts, it's not at all uncommon for a tourist to plug something in, and have the power go out coincidentially. Always check the neighborhood first, before blaming the appliance.

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