Lathe nameplate info

Discussion in 'General Electronics Chat' started by matt11111, May 12, 2009.

  1. matt11111

    Thread Starter Member

    May 12, 2009
    I am trying to determine the current/power consumption by a lathe which consists of 3 AC motors.
    There are nameplates on all individual motors that state information such as
    supply voltage

    I need to know the overall current/power draw of the machine as a whole.
    How would I go about doing this?
  2. jpanhalt


    Jan 18, 2008
    Supply voltage times FLA (full load amps) will give a value in VA. You can add the VA's together to approximate what you will need at a maximum. If they are all at the same supply voltage and phase (e.g., 3 phase), then it is relatively simple. If some are single phase at one voltage others are 3 phase at another voltage, then you need to consider losses from conversion. Finally, adding the maximum power needs may over estimate your needs, if it is unlikely all three motors will be running at the same time at maximum power.

    This is just a guess, but if you are planning for a 3-phase converter, remember that the power of the converter only has to match/exceed the largest motor. Once that motor is running, you can start the others.