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

Motor Stall Current

  1. Aug 7, 2014 #1
    Hi,

    I am currently doing my Master project and unfortunately did a rookie mistake.
    My DC motor is mechanically linked to a loaded PMA (wind turbine generator) and I need to run it at a variable speed. All this is built, however when choosing my PSU, I forgot to take into account the stall current (which was unfortunately not indicated in the motor's datasheet. My motor is rated at around 600W (3/4 HP to be precise) with 24V (so a current of 25A). My PSU is the same, 24V and 25A rated. My whole system is built, the motor starts for 1 second and then the PSU stops working (very probably due to overloading). I am therefore unable to start my motor at all.

    Would any of you have a solution for me to jump-start my motor without having to replace the whole PSU (which is quite expensive)? I still do not have a measurement of stall current, but I ordered a meter shunt to help make my measurements.

    Datasheet:
    OMPMDC34-18-24V-56C :
    http://www.omega.com/Auto/pdf/OMPM-DC.pdf

    Thank You for your help.

    maxstag
     
  2. jcsd
  3. Aug 7, 2014 #2

    Baluncore

    User Avatar
    Science Advisor

    The quick and dirty solution would be a 1 ohm series resistor rated about 600 watt. Instead of a resistor, I would consider using 24V 100W truck headlamp globes, maybe 4 to 6 of them in parallel. That will limit current during start-up, globes will then go dim and low resistance once motor is running. Maybe a parallel switch to short the globes for maximum power.

    Alternatively, make a switching current limiter.
     
  4. Aug 7, 2014 #3

    jim hardy

    User Avatar
    Science Advisor
    Gold Member
    2016 Award

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Motor Stall Current
  1. Current through a motor (Replies: 17)

Loading...