motor run capacitors in a power supply

Discussion in 'The Projects Forum' started by jrros, Mar 14, 2012.

  1. jrros

    Thread Starter New Member

    Mar 17, 2011
    Hello this is my first post I have a question about a 80mf 440v
    motor run capacitor. A power supply Im building requires 2- 80mf 440v
    caps I have 2 motor run caps with no polarity. Can they be used?
    if so do I have to have a + side? There brand new made in china.
    Thanks Jerry
  2. #12


    Nov 30, 2010
    Motor caps have terrible voltage dependency...they change capacitance depending on what voltage is across them. You can try them. They don't have a polarity. If they are oil filled caps they will survive (unless they are cheap crap from chyna). If they are "dry electrolytic" the ripple current might make them start smoking. That's a sure sign they are about to blow up.