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Effects of reduced voltage on an induction motor

  1. Feb 12, 2010 #1

    pip

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    if the motor is already running at a voltage of 410V what would the effects be of reducing the voltage?
     
  2. jcsd
  3. Feb 12, 2010 #2
    Is this a multi-horsepower induction motor designed for 3-phase 440/480 V at 50 or 60 Hz? Induction motors like to run at the correct voltage and synchronous frequency, and draw current whenever the RPM drops below the synchronous RPM. When the input voltage drops at a specific load, the input current increases in order to maintain the correct loaded RPM (e.g., 1740 RPM for a 4 pole motor at 60 Hz).

    Bob S
     
  4. Feb 14, 2010 #3

    pip

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    yes this is a multi-horsepower induction motor designed for 3-phase 440V at 50Hz
     
  5. Feb 14, 2010 #4
    With only 410 volts, the motor may draw excessive current in order to run at say 1450 RPM at full load . Excessive current increases the resistive losses (I-squared R). I have actually run induction motors at undervoltage conditions and have seen the current increase. The one good thing is that the power factor improves..
    Bob S
     
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