Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

RPM vs power consumption

  1. May 14, 2017 #1
    hi, i have a study on a plucker machine and it came out that when the rotational speed of the plate is low, the power consumption rate is high and if the rotational speed is high, the pcr is low.

    what is the possible explanation for that? thanks in advace.
  2. jcsd
  3. May 14, 2017 #2


    User Avatar
    Science Advisor

    The speed is controlled by a brake, not by changing the voltage (or frequency) to the motor.
  4. May 18, 2017 #3


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Could be the nature of the load. For example consider a horizontal axis drum .. at low speeds the contents are lifted and fall down but at high speed they stick to the drum and rotate with it.
  5. May 18, 2017 #4
    Could they be referring to efficiency (chickens plucked per watt-hour increases with speed) versus absolute power consumption at each speed?
  6. May 19, 2017 #5

    jim hardy

    User Avatar
    Science Advisor
    Gold Member

  7. May 19, 2017 #6
    "I have a study" - -what study, what type of motor? At low speed - a standard induction motor has high slip, high current, lower power. However in an application at low speed the motor will use all of the torque available to try to accelerate - at full speed, it is probably not fully loaded, but then it has bad PF. If YOU did the study - how did you measure power? -- If only V x A and did not include PF... ( Motor curves are like a current ratings - typically "what is available", in an application you are not ON the motor curve - you are somewhere "below" it)

    Side note - I did a job in Trinidad and they had "Cluck and Pluck" stores - like a laundromat. You bring in your chickens and cluck and pluck them. As a east cost USA guy, it was the weirdest thing I have ever seen.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted