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Transformers connection

  1. Apr 2, 2010 #1
    hi guys,
    I want to know if it is always possible to link two transformers in series with different rated voltage. And if there is any concern about the polarity.
    If it is not possible in which conditions it can be done?
  2. jcsd
  3. Apr 2, 2010 #2


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    Staff: Mentor

    What do you mean by linking them in series? Why would you do that? It's done in some multi-configuration transformers (like ones that are used in both 110Vrms and 220Vrms applications), but in general, I don't know why you would do this. Can you explain the context a bit more?
  4. Apr 2, 2010 #3


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    Science Advisor

    Yes, you can connect transformer primaries or secondaries in series.

    You just have to be careful not to exceed the rated voltage or current of either device.

    It is most often done to get a higher voltage on a secondary output by connecting lower voltage secondaries in series.
    It is important to get the phase right, but if you get it wrong, the voltages just subtract rather than add.
    Nothing bad happens, so you just reconnect them.

    Do you have an application that may need this?
  5. Apr 2, 2010 #4
    Ok. When I link three monofasic transformers in delta or star what are the concerns to take about the polarity, capacity, rated current and tension?
  6. Apr 2, 2010 #5
    Be sure to preserve phase from primary to secondary, or you will end up with some peculiar voltage combinations. You don't want to exceed the transformer's VA rating in any given leg.

    It's also possible to convert from delta to Y, or Y to delta using three single phase transformers, by the way.
  7. Apr 3, 2010 #6


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    Gold Member

    I like this winding configuration paper which may be of interest to you.
    Last edited by a moderator: Apr 25, 2017
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