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Power freq 50hz or 60hz issue


TheBroker
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Hello, just want to know if the power outlet frequency will have a drastic effect on the electrical appliances? Say for example:
- If I buy an electrical appliance from another country whose power spec is 220V, 50Hz, then I bring this item to another country whose power spec is 220V, 60Hz, will the 10Hz difference will damage the equipment or affect it in any other drastic way?
I think those motor-driven/transformer-supplied appliances will be affected (like air-conditioner, fridge, TV, etc), but I just want to make sure. So please advise. Thanks!

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It depends on the appliance type and sometimes on the appliance itself.  Some things, like small power tools, blenders,  and devices with a switching power supply (computers, televisions, VCRs) are not likely to complain about going from 50Hz to 60Hz, but some might.

Things with AC motors like laundry, refrigerator, and air conditioning will change their behavior with different frequencies.  If this causes a increase in the current then it may be destructive.

Many clocks won't keep correct time.  Good luck.

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The answer is complex and requires some knowlege of the nature of the specific equipment you want to change power frequency on.

In general, induction motor driven equipment will be OK with higher than design frequency power, but not lower, but you have to check what the increased speed of a 50 Hz. motor powered with 60 Hz will be.  If the higher motor speed can be adjusted out by, say, a pulley change, then the increased frequency will definitely be no problem.  Some loads will overload the motor due to the increased power consumption at higher speed.  The 50 Hz induction motor powered by 60 Hz can actually produce more than its rated power but it may not be enough to compensate for the increased power demanded by the oversped load.  The increased power output of the motor is due to the larger amount of iron and steel that a 50 Hz motor of a given rated power is built with.

In general, a 60 Hz induction motor cannot be operated at 50 Hz unless it was designed as a 50/60 Hz, dual frequency motor, as many are.  Look at the nameplate.  The basic problem is that an induction motor designed for 60 Hz only will magnetically saturate on 50 Hz power because there is not enough copper and steel in the motor.  Saturation leads to greatly increased current and burnout.

Most devices that rectify the incoming power to provide DC to the load will be OK going to a higher frequency because most power transformers will be fine with increased frequency and the ripple on the storage capacitors will actually be lower than the equipment was designed for.  Going to a lower frequency will generally be OK if there is no transformer or if the transformer is rated 50/60 Hz.  You have to check if the device can tolerate the larger ripple content of the rectified 50 Hz power.  You should also check whether there is a motor in the device, like a fan.  Here, again, if the fan is designed for 60 Hz only, it may saturate on 50 Hz.

Equipment powered by brush motors, like most hand-held power tools, will generally be tolerant of frequency change in either direction because, unlike induction motors, their speed is independent of power frequency and because they are not subject to magnetic saturation due to reduced power frequency.

Anything with a critical speed or timing function that uses an induction motor driven clock or timer will be off speed/time by the ratio of the frequency change.

A device with a large power transformer like a transformer welding machine cannot tolerate reduced power frequency unless specifically designed for 50/60 Hz.  In general, going to a higher than design frequency would be OK, but be careful about overspeeding fans.

So the answer to your question is "sometimes," but always check with the factory, if possible, or make sure you know what is happening inside the box.

Good luck!

awright

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  • 1 month later...

The answer used to be a simple yes, but no longer.  High efficiency clothes washers like the new front-loaders often use switched reluctance motors instead of induction motors because switched reluctance motors driven by sophisticated electronics can provide easy reversability and a wide range of operating speeds, thus allowing elimination of transmissions otherwise required for the speeds and direction changes of the various washer functions.

Almost all refrigerators use induction motors sealed with oil in a hermetically sealed case.  These refrigeration compressor systems are highly optimized for the function and should only be operated at voltages and frequencies mentioned on the embossed label welded to the case.

I don't know about dryers.  Since older models tended to operate at a single speed, with only the heat or drying time varying, most of them had incuction motors driving a long belt wrapped around the drum.  Newer, high efficiency models may also have multiple speeds, which would imply a switched reluctance motor.

Since a switched reluctance motor is electronically driven, it MAY be tolerant of power frequency variation. I do not know.  Speed of a switched reluctance motor is not power frequency dependent.  Best to check frequency tolerance with the manufacturer if at all possible.

You should be able to observe whether your appliance has a switched reluctance motor by looking at the wires going into the motor.  Most appliance induction motors will have two conductors entering the motor (plus a ground conductor connected to the frame), although this is not universal.  If the motor has many wires entering it and if there is a somewhat complex circuit board with some large power semoconductors on it, you probably have a switched reluctance motor.  That's very good for efficiency and simplicity of design.

awright

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maybe the motors will turn faster , thus the timer for the cycles faster too!!!
this would mean your 1 hour cycle for coloured items will only last about 50 mins.
it could be ecologically a good move to go from 50hz to 60hz.
If you go to 50hz from 60, you might burn out the ozone layer a little faster, if not your motor!!!

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