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117V AC appliance on 127V AC mains?

  1. Apr 13, 2010 #1


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    In parts of Brazil, the mains voltage is 127V AC. Is it safe to use an appliance which is supposed to take 117V AC in this situation?
  2. jcsd
  3. Apr 13, 2010 #2


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    You would have to check the ratings of the equipment.

    If the mains is a nominal 127 volts, this may mean 127 volts plus or minus 10 %.
    So, you could get voltages between 114 volts and 139 volts. (In many places it could be worse than that, of course, but this is just looking at the ratings)

    If the equipment was rated at 117 volts plus or minus 10 %, this would mean it would be safe to operate it between 105 volts and 128 volts.

    So, it would depend on the actual voltage available. If the mains were always on the nominal voltage or on the low side of it, you would be OK.

    To be safe, you should probably be using an auto-transformer to reduce the voltage.
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