Induction motor

Discussion in 'Homework Help' started by cpleng7, Aug 15, 2010.

  1. cpleng7

    Thread Starter Active Member

    Dec 18, 2008
    120
    0
    Did anyone know how to calculate the maximum load that 4 hp class F induction motor can sustain?
     
  2. cpleng7

    Thread Starter Active Member

    Dec 18, 2008
    120
    0
    how to i know the induction motor is in full load condition
     
  3. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    Well, most motors are rated with a "LRA" or Locked Rotor Amps number.

    This number shows the amp draw when the motor just starts, or if the load caused the motor shaft to stop spinning.
     
  4. sify87

    New Member

    Jun 23, 2010
    9
    0
    Ok! First of all u cannot find a motor of 4HP.The Full Load Current of a 3HP motor is 4.8A and a 5HP motor is 7.8A.U jst use the simple formula
    P(kw)=1.732 X V X I X pf X Efficiency.
    So, for a 4HP motor(although u cannot find it) change the rating of motor from HP to watt,voltage-415V,pf-0.8,Eff-0.8(assuming) and u jst calculate it.Thanks!!
     
  5. cpleng7

    Thread Starter Active Member

    Dec 18, 2008
    120
    0
    if I add some weight to the shaft is that consider the load for the induction motor?
     
  6. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    Yes. Any weight or force on the shaft is the "load".
     
  7. sify87

    New Member

    Jun 23, 2010
    9
    0
    Ok! how can u add some weight to the rotating shaft??
    Basically the motor shaft is coupled to the pumps or conveyors or etc. Now when the motor is started then it is said that the motor is in load condition.In this condition two types of load acts on the motor shaft
    axial load & radial load.
    If the motor is started when the shaft is in de-coupled condition then it is said motor in no-load condition.
    Thanks!!
     
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