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240 @ 50hz to 120V @ 60Hz
December 11, 2012 3:49 AM   Subscribe

I need to find about 10 transformers/converters from 240 @ 50hz to 120V @ 60Hz capable of about at least 1000W @ 120V.

I would probably not be able to figure out how to build them so |I am looking to buy them.

I find a lot of converters from 240V to 120V but they do not adjust the frequency. I do realize that its much more difficult to accomplish the frequency change.

My ideal situation would be a central unit so I could pay a professional to install it and run wires around the appartmnet.

However I would be fully happy with 10 small boxes.
posted by digividal to Technology (17 answers total)
 
I do realize that its much more difficult to accomplish the frequency change.

This is actually pretty standard stuff - the term you're looking for there is "voltage converter transformer" and they're a pretty standard accessory for travellers. This is one example, and there are plenty of others.

I don't understand the situation you find yourself in, though - many modern laptops and many small appliances have power adapters that handle both just fine; if you're doing this because you're working overseas and bringing a lot of small appliances with you?
posted by mhoye at 4:57 AM on December 11, 2012


Thank you for your answer.

The item you linked to does convert the voltage but does not change the frequency.
Finding the pure voltage converters is pretty easy, but finding the voltage + freq
seems to be hard.

Due to lots of various circumstances I find myself with quite a few items that require a different voltage and frequency including small appliances, a tv and quite a few other items.
posted by digividal at 5:16 AM on December 11, 2012


You can find them, but the cost (even for one unit) is likely to be far greater than simply replacing all your appliances.

http://www.zrd.com/faq/esdfaq60hz.html is an example -- costs *begin* at US$4800 for a 3kVA unit.

If you're talking about serious lab equipment, then it might be worth it.
posted by nonspecialist at 5:23 AM on December 11, 2012


Hey there thank you nonspecialist. I bow to your superior searching skills or education or both. Plus you are a very nice person.

Its just what I needed, though I agree the cost is rather excessive.

I will have to make a spreadsheet and compare.
posted by digividal at 5:39 AM on December 11, 2012


Here's one that can handle up to 1000w, and does the frequency conversion, too - less than 60 bucks. They have a 2000w one for $85, too.
posted by Slap*Happy at 5:47 AM on December 11, 2012


You can actually run some appliances at the wrong frequency, 60hz motors will run at 50hz, but may overheat, and they will have less power. A heating element should still work, but that'll be a big transformer (1600W minimum). Double check your TV, I know some LCD's will take 50/60hz. Computers should be fine (There is a switch on the back of the powersupply if you have a desktop). Laptop power bricks and most chargers take 220V just fine. (you can also buy a new universal 'wall wart' for not much in your destination country if you have ones that don't take 220v)
posted by defcom1 at 5:47 AM on December 11, 2012


Slap*Happy, that one doesn't do frequency conversion, it's just happy with either frequency and will pass that through. (Step up/down transformer). The only way to change the frequency is with a transformer-rectifier (or motor-generator set(!)). Details on wikipedia. A transformer-rectifier is more expensive, it's got a pile of solid-state power electronics in it, hence the price as found by nonspecialist.
posted by defcom1 at 5:54 AM on December 11, 2012 [1 favorite]


Slap*Happy, that one doesn't do frequency conversion, it's just happy with either frequency and will pass that through.

True enough, but it is exactly what the solution calls for. Unless you're driving an old-fashioned mechanical clock, the change from 50Hz to 60Hz and vice-versa makes no difference.

My ideal situation would be a central unit so I could pay a professional to install it and run wires around the appartmnet.

I do this in my flat in Stockholm (vice-versa). I have a heavy boat-anchor step-down transformer plugged into the mains and the output is connected to a long power strip providing 110VAC. Those individual solid-state converters are horribly inefficient compared to an old-fashioned transformer and you don't need more than that so why waste the energy?
posted by three blind mice at 6:01 AM on December 11, 2012


I have contacted the makers of several of the items involved and according to them it will require a change in frequency as well.
posted by digividal at 6:22 AM on December 11, 2012


defcom1 writes "Computers should be fine (There is a switch on the back of the powersupply if you have a desktop)."

The switch on desktop pcs switches between different voltages not frequencies.
posted by Mitheral at 6:30 AM on December 11, 2012


Yeah, but switched mode power supplies (like you have in desktop PCs) really don't care what frequency you feed them in the first place.
posted by pharm at 6:43 AM on December 11, 2012


Slap*Happy's device will definitely not change frequency. No cheap voltage converter will.
posted by ryanrs at 9:30 AM on December 11, 2012


I come across this problem on foreign offshore vessels from time to time. Most of the equipment I used can handle 120V/240V at 50 or 60Hz, but we use UPS for power backup and the normal ones we have available are 120V only, so we use an isolated transformer to convert everything to 120V. Then there is the 50Hz issue. Somewhere on every device that plugs in, there should be a rating for the acceptable power input. If it is rated 50/60Hz it does not matter. If it is only rated for 60Hz, I understand it either means it will catch on fire if you apply 50Hz power or they just did not test for 50Hz. Always assume the smoke and fire scenario.

90% of our equipment is rated for 50/60Hz, but I have learned not to take a chance with the rest. My solution is to use a DC power supply to convert the 120V 50Hz to 12V DC, then use an inverter to convert the 12V DC to 120V 60Hz. If your apartment is wired for 240V, I am assuming you can find 240V AC to 12V DC converters (~10A) in your area, then order some 1000W inverters which should be $50-$100 range. You will have 2 boxes instead of 1 and it is not the most electrically efficient configuration, but is the only way I know of that works with a reasonable price.

The one problem with this is that depending of the quality of the inverter, you will end up with a mostly square wave instead of a clean sine wave. If you are going to sensitive electronics like sound equipment it may not like that too well.
posted by Yorrick at 12:44 PM on December 11, 2012


You may be able to find an uninterpretable power supply(UPS) that will take 50hz input and still output 60hz. Typically a UPS works by rectifying the mains sine wave to charge a battery which is then inverted back to a sine wave to run equipment, so really the inverter could be designed to output whatever frequency is desired. That said, most UPS units will have an output frequency that is linked to the input so that they don't have to run off the battery all the time and via use of an autotransformer they can bump up the output voltage to fight brown outs. These configurations will not change the frequency of the output voltage.

Another thing to keep in mind, as Yorrick talked about, is the quality of the output waveform of an inverter. If you have a sensitive piece of equipment that needs an input voltage that is truer to a sine wave than a square wave you will have issues with a cheaper frequency converter/UPS set up.
posted by Quack at 3:25 PM on December 11, 2012


Found a good thread where people are talking about a UPS that setup that would work. It looks like the keyword is Online UPS. It would allow you to change the output frequency of the inverter. Note that they look quite pricey.
posted by Quack at 3:29 PM on December 11, 2012 [1 favorite]


What you want is a double conversion / true online type UPS.

In this arrangement the UPS has a battery. The battery is being constantly charged or kept at float voltage from the AC wall supply. This is a separate part of the UPS which is an AC (whatever input voltage) to DC, 12V, 24V, 48V charge controller.

Simultaneously the battery is constantly feeding the input of a DC to AC true sinewave inverter, to which you will connect your loads. The output of this sinewave inverter is configurable depending on the model of UPS you purchase. When the power goes out all that happens is the battery charger stops working.

These are at most 92% efficient. They are also more expensive than other types of UPS, starting at around $450 for a very small one.
posted by thewalrus at 4:18 PM on December 11, 2012


I need to find about 10 transformers/converters from 240 @ 50hz to 120V @ 60Hz capable of about at least 1000W @ 120V

10 units rated @1000W? That's quite a load...

Most stuff does not care about the frequency:
Anything with a switch-mode power supply [i.e. most modern electronics] doesn't care.
Any resistive devices [i.e things that get hot, like toasters, electric kettles etc] don't care.

Items with synchronous motors do care, but you're unlikely to have many of them.
Items with transformers rated for 60Hz operation will run hotter when run @ 50Hz, but you're unlikely to have many high powered items that do that.

If you make a list of all your items, and inspect the power requirements label of all of them you'll find they fall into three groups:

1) Stuff that doesn't care about voltage or frequency
2) Stuff that cares about voltage
3) Stuff that cares about voltage and frequency

1) will be fine with just plug adapters
2) will be fine with suitably rated transformers
3) will need either replacement or run via a transformer + UPS/inverter

You will probably find that the wattage you require for 3 will be fairly modest, and thus you'll spend less than if you try to run everything this way.
posted by HiroProtagonist at 4:25 PM on December 11, 2012


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