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What is rated load ?

  1. Apr 17, 2007 #1
    What is "rated load"?

    What is "rated load" and what is its relationship to rated voltage and current?

    Part of the question:
    "Assume the transformer is supplying rated load at 480 V and 0.8 PF lagging. What is the transformer's input voltage?"

    I'm not asking for help with actually working out the problem, I just need to know what that term means. Any help is welcome. Thanks!
  2. jcsd
  3. Apr 17, 2007 #2


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    Rated load is the maximum power output the transformer was designed to handle.

    How are rated voltage and current related to power?
  4. Apr 20, 2007 #3


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    A transformers "rated load" is rated in VA (volts X amps), not power (since the manufacturer has no idea what kind of load will be put on it).

    The rating of the transformer is based on the heat build up from current flow through the windings. At rated voltage and rated amps, you would have 100% of rated load in terms of kva, but only 80% Kw with a .8 power factor.
    Without knowing which they are referring to in terms of "load", the voltage part of the question is irrelevant.

    If the quiz question is stated correctly in your post, it is poorly worded.
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