Electrical Engineering/Using an electrical appliance in different countries
QUESTION: Hello Cleggsan,
I am wondering if you can clear something up for me. If I am travelling from one country to another, can I use a different power cable for each country with the same device? The device has a slot for the power cable. Can I just put in a new power cable with a different plug that fits the socket of another country? Is there anything else that effects whether this will work? Different voltages perhaps?
Thanks as always!
ANSWER: Unfortunately you must consider each appliance and each country to be safe. For example, many appliances are frequency dependent. USA appliances are designed to work on 60Hz whereas most but not all European countries are 50 Hz. And the complication does not end there; some appliances will work ok with either frequency but some will not. Some may work ok even though the manufacturer recommends against it.
Most electronics stuff such as computers or tvs will work with either frequency so long as the voltage is correct. And, some computer power supplies have switching type power supplies that will work with any voltage or any frequency!
Above is a good guide to countries of the world and their voltage, frequency and connector design.
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QUESTION: Thanks Cleggsan,
When an electrical device is designed and manufactured, what factors govern whether it will work okay with either frequency?
I am trying to understand why devices are made that work in one place but not another. Is it the internal components used in a device that determine what voltages and frequencies it will work with? What are some of the common reasons why it might be difficult or expensive to manufacture a device that works with both 50Hz and 60Hz?
Appliances are designed to work with, in the most part, the public energy system. I sent you previously the listing of power systems used by all the countries of the world.
Most appliances are designed for optimum useage from the power system of the country in which it is being sold.
Voltage conversion to the proper level is easy to do since it only requires a transformer to change the voltage feeding the appliance to the proper voltage. The key ingredient in this matter is the power transformer used. Some appliance makers use transformers with dual connections so that the operating voltage can be adjusted to different countries but that is not a common practice.
The other factor is frequency. The power systems of the world normally work on either 50Hz or 60Hz systems. Motor speed and operation is dependent upon the frequency of the power. Take for example an audio turntable which spins the platter at the proper speed. If the line frequency changes it changes the speed of rotation of the platter.
Heavy appliances such as washing machines, refrigerators and such use motors optimized for the frequency being supplied in the market.
Changing frequency is very difficult; the system power must be converted to a dc power and the dc power is then fed into a dc to ac converter at the new frequency. Such conversion is very expensive and requires a bulky piece of machinery.
That explanation is enough for you?
Let me know if you need more.