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Transformer help please -- AC Mains transformers of different input voltages

  1. Dec 17, 2014 #1
    Does anyone know if there's any safety or performance issues with going about the input voltage of a transformer? The spec on maplin says on just about every step down transformer that the input is (x)v-230v. As I live in the uk, mains voltages are 240v a.c. Not sure about what to do
  2. jcsd
  3. Dec 17, 2014 #2
    For sure you can use 230V transformer, and nothing bad will happen. But you should never try to connect a 120V transformer into 240V mains.
  4. Dec 17, 2014 #3
    Will work fine. That's within 5% of a rated voltage. BTW if you measure mains voltage during a day, it rarely reaches claimed 240 V rms. I also live in Europe, in area where official mains voltage is 230 V. At home I measure between 220 and 225 V.
  5. Dec 17, 2014 #4


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    What's a maplin?
  6. Dec 17, 2014 #5

    jim hardy

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    Make sure it's rated for that voltage at your line frequency.
    Are you 50 hz over there ? .
    We're 60 hz here and nominal voltage is 240. We measure 252 volts at my friend's house on days when utility load is light.

    At 50 hz , transformer iron carries 20% more magnetic flux than for same voltage at 60 hz.
    Its hum will be noticeably louder if it's in trouble...
    It'd be just my luck to get a transformer made for 60 hz only.
  7. Dec 17, 2014 #6


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    1. It's nerdy young man who works in a shop and knows the spec of every bit of electronic kit they have for sale.
    2. It's a UK chain of shops / internet order company.
  8. Dec 17, 2014 #7
    Jim, it is 50 Hz in UK . At least, it was that last time I was there ;)
  9. Dec 17, 2014 #8


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    Oil lamps and candles mostly, over here, actually.
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