Can I use a fridge 110v 60hz in a country w/ 220v 50hz with a power inverter that lowers the 220v to 110v bt can not change the 60hz to 50hz obviously?
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Can I use a fridge 110v 60hz in a country w/ 220v 50hz with a power inverter that lowers the 220v to 110v bt can not change the 60hz to 50hz obviously?
It is the frequency that determines the speed of a motor not the voltage. If you had a 4 pole motor rated at 50hz then the speed would be determined by the following formula:
(seconds in minute x frequency/pole pairs) - friction losses.
friction losses can vary but are normally around 4%. So for this motor the speed can be determined as:
60 x 50/2 - 4% =1440rpm
If you had the same motor running at 60 hz then the speed would be 60 x 60/2 - 4% = 1728rpm - this is an increase of 20% so the amp draw would be increased, the heat generated by the motor would be increased but the life of the motor would be shortened.
The answer to your question is yes - but not for long!
Frank
Although it isn't clear, I'm thinking the question involves running a 60hz unit on 50hz power, in which case the opposite would apply.
The unit's capacity would be reduced by about 20%, and less heat would be generated. In other words, it wouldn't hurt the system (assuming the voltage is correct), but it may not have enough cooling capacity to do the job.
Gary
I agree, but when the motor is wound for 60hz then exactly what I've said happens.
Frank
Thanks for your help.
I have found a fridge with specifications of 50hz/60hz - is it possible to have a motor that switches or does it make more sense that it is a 60hz motor that will work on 50hz power?
We've had quite a few problems with 60hz cam timers on York condensing units. These units are manufactured in the US, shipped to France or thereabouts, the wiring is changed to comply with CE markings and then finally shipped to the UK for installation.
Because the cam timers are wound for 60hz, when they are operated on 50hz the get really hot and eventually burn out. Even York admit they are a constant problem.
I've seen many a 60hz fan motor "melted" after being run at 50 hz.
Frank
dk
Does the compressor name plate give 2 running currents for the different frequencies?
Hi
the problem is very simple to understand.
Operating at 50hz will slow the rotor.The speed of an induction motor is given by 120*frequency/no pole of motor less 4% for full load speed.
The BIG problem comes when you transform the voltage to 110v ac 50 hz. This violates the rated airgap flux of the motor and results in magnetic saturation giving rise to EXcessive heating!!!!
To overcome this the voltage/frequency ratio must be maintained as the frequency is changed. A typical VSD does this in ausie slang we calll them VVVf drives ie variable voltage variable frequency drives.
to fix your problem your motor's native volatge frequency is 110v/60 must equal ?/50
?=92V if you fed your compressor 92V@50hz via a cutom made transformer it will work perfectly.The speed will be lower but the motor will be more energy efficient as its iron losses are lower when operated at the corect voltage at reduced frequencies.
I know this as i commision and design variable drive systems for motors rated 10kw to 10 megawatts. Its always boils back to the same basics.
I have two peices of machinery that are designed to run at 240 @ 50Hz, How would they opperate at 208V @ 60Hz?
I don't think any thing would be need doing as the voltage drops with the gain in frequancy but you'd know better!
Thanks.
Hi
If you operate a 240v 50hz compressor on 208v 60 hz it is likely to stall if you chrge it up fully. The reason now is you have reduced the volatge per hertz ratio which will cut the torque availble to the compressor by a square of the volatge reduction percentage.
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This means if this 50hz compressor is to operate in a 60hz supply you will have to feed that baby 288V!!!
but you are only giving it 208 V.
(208/288)squared = 0.52 which means its likely to halve its available torque which means it will opeate slower than when it was on 50Hz and worse is it will operate hotter and stall easier due to excess slip of the induction motor.
Looks like the only way you can get good results with this one is to operate it at a bit less than 50% capacity at 208V60hz or less or risk stalling and overheating on aconstant basis.
My thoughts are it will be an abortion.
If it's just a fridge, then yes, I've seen a fair few in australia run for years. Most of the posts here are comparing more complicated things than a basic fridge.Quote:
Originally Posted by dkupinsky
You will lose some performance and defrost cycles will be out, but it will work.
But then again, a transformer to run them aren't cheap, and moving something as heavy as a fridge internationally isn't cheap. You're better off to buy one to suit local mains supply in the country with a different voltage/frequency.
Most things that are desgined to run in countries with 240v mains are actually rated at 220v. For example here in australia most houses have 230-250v mains, the most common being 240v, But all the gear we get here is rated for 220V and the national standard to 230v.Quote:
Originally Posted by The MG Pony
That being said, I've seen stuff fall over and die at 217V. so I don't see much hope on running them at 208V.
What you're asking them to do here is run faster at less voltage, even less of a chance of them running at 50hz and 208v which is a big ask in itself
Slightly confusing the situation. I have bought 115V 60HZ POWER TOOLS from USA working on the premise that running through a 110v 50hz transformer. They would just run slightly slower and draw less amps.
So far it has proved to be a very very cheap source of Industrial grade (110v) power tools.
Which appear to run fine!
Is that correct?
Grizzly
ps Has anyone noticed how old this thread is?
More often than not what happens is that someone will be looking through threads and reply to a post without realising that it is out of date.Quote:
Originally Posted by Grizzly
Then people answer their posts and hey presto the thread is alive again.
you won't catch me replying to old posts:p.
taz
Good info from Frank and Gary but it looks like Tsangep is " THE man of the moment " when it comes to motors and frequencies - so ,,,, it's good to meet you online Tsangep, :) no doubt we will call on your motor knowledge further.
Attached is something useful for readers, perhaps - it deals more specifically with 3 phase power : a little old but this solid info never goes out of fashion.
It's along the same line as Tsangep said about any frequency variation should be in same ratio as the voltage variation ( or conversely). I.E. running a 460/3/60 rated motor on 380/3/50 supply.
best regards
T-P
Well if any one is curious the equipment was a nice washer & drier from Switzerland, it is now running on a 230V circuit as messured at the plug and seems to be doing fine.Need to replace the timer motor though with a 60Hz wound one lol.
Dear Gentleman;<O:p</O:p
I have 250 Pcs of Trane Air-condition 50Hz ,in saudia <ST1:pArabia</ST1:place we have 60 Hz ;If their is any converters in the market or solution to convert it please advise me.
<O:p></O:p>
Best Regards
There is nothing which cost less than air conditioner itself.Quote:
Originally Posted by e_alfares
Hello,
I would like to as what happens if I use a Black& decker jigsaw that I bought from US,in Europe.
I want to use a voltage converter from 220V to 110V but I'm warried about the frequency...for US is 60 and 50 in Europe.
Is there any risck if I use it at 110V - 50 hz?
is there a way to obtain 110V - 60 Hz from 220 V -50 Hz
Thank you
Did you read anything what was written in this thread before you posted this question?:rolleyes:Quote:
Originally Posted by flavius005
It seems by your calculation below that the motor would run at a slower speed at 50hz than at 60hz... so why would it burn out?
I suppose in a refrigeration application it would have to run longer to get the same work done.... and since it is running slower, whatever cooling facility it had would be less efficient.
What a shame... I would love to buy appliances that would work both in the U.S. and in Europe. Where in the world did they get the idea of 50hz in the first place? 220V I can understand... copper is more efficiently utilized...but alas homeowners are more likely to be killed at 220V.
Many thanks for the physics lesson.
- Bob
Quote:
Originally Posted by frank
I am used to a lot of USA equipment rated 60hz here in Europe. We sold many blood bank fridges and on them they simply made a step down trafo 100v to make the correct voltage. The units with a small Copeland works well and many units out there is more than 20 Years old. The even more strange is that they used a currrent type start relay who had to kick in about every 3 minutes(X20Years). What a quality on those parts.An important issue is that a slower rotating compressor (50hz)sucks a lot more of amperage than on 60hz. Copeland 115volt 60hz and 100volt only on 50hz to prevent the current and heat to destroy them. Copeland is more aggresive to rate the voltage these days. The ultra low temperature freezers with Copelands we trade are rated 208-230 at 60hz and only 200volt at 50hz. The lower speed make fewer changes of the impedance who gives less resistance and make them to suck quite higher amperage for sure. A little on the side, but a product as a contactor rated at 60hz draws same way because the impedance to a higher amperage. I have equipment burning those coils and the US marked never saw it due to their less amp/heat over them by 60hz.
Another maker who produce all kind of waterchillers/circulators had only one extra in the specification and that was a 17% capacity reduction if used on 50hz and it was approx. the truth too. Never saw a reduced lifetime on them, but the ULT units we trade get a shorter lifetime to at a beginning to hard working low stage compressors.
So technical.im with grizzly.an old recip on r22@50hz eg carrier120 rated at 60hzwas charged with r500 and the refrigerant seemed to solve the issue .or is that the issue?