Grounding cable in Hybrid Vehicle

Discussion in 'Automotive Electronics' started by Petros.Alexakis, Sep 1, 2016.

  1. Petros.Alexakis

    Thread Starter New Member

    Mar 10, 2016

    I have a question. On an automotive 48V system that the phase current is 200A is there a way to calculate the size of the ground cable you need to use?
  2. crutschow


    Mar 14, 2008
    Of course, it's not guess work. :rolleyes:
    You determine how much voltage drop you can tolerate for the resistance of that length of cable and then look in a wire table to determine what wire size has a resistance no higher than that for that length.
  3. tranzz4md


    Apr 10, 2015
    So, for example, 3℅ is considered a reasonable but fairly low voltage drop. A car is maybe a 20' circuit, #3 wire probably won't get too hot, unless that ampacity is pretty constant, and the resistance for 20' is 0.00508 (0.254 per 1000), and your voltage drop is close to 1V - close to 2%.

    I'm uncertain of your application, but suspect that conductor heating may be a larger concern than voltage drop. I also work more with higher voltages and greater distances typically, but I can't imagine why considering a smaller conductor would be defensible for the small quantity of wire needed.

    Best of luck!