fuse

Discussion in 'General Questions' started by irv, Apr 24, 2010.

  1. irv

    irv WindyNation Engineer

    what to use to fuse the dump load ? have two WN resistors . also a fuse for the WN pma 500 between it and the batterys . will be useing 8 golf cart batterys . thanks
     
  2. TomT

    TomT WindyNation Engineer

    Had to think on this one for a while. I would say 60amps.

    My resistors I just got are .73 ohms which works out to 197.26 watts at 12 volts.
    It is possible that this is the start-up current. As it heats it will lose resistance and come up to the full 300watts at 25amps each for a total of 50watts.

    Confused yet?

    Also from doing wiring I found out that is not good to run wire and fuses at there full rating. Cause for heating and failure. So we always build in 20 percent for safety and to cut down on wasted power thru heating in the wires and connections.
    .So 50 * .2 =10 add 50 +10 you get 60amps.
     
  3. irv

    irv WindyNation Engineer

    thanks , 60 amps it is . now ,, what kind of fuse to buy ????
     
  4. TomT

    TomT WindyNation Engineer

    I did some more testing and will post pictures. This is one way to do it. The light socket is rated at 660W and should work fine. A standard plug fuse will screw right in.
    If you break up the circuit so each resistor has a 30 amp fuse. Then If something should go wrong with one the others will still be used as a dump load.
     

    Attached Files:

  5. TomT

    TomT WindyNation Engineer

    Picture #2
     

    Attached Files:

  6. TomT

    TomT WindyNation Engineer

    I was wrong stick with 12v stuff. I checked with the auto parts and they have 30 amp atc and ato blade fuse holders.
     
  7. TomT

    TomT WindyNation Engineer

    I did some more testing and will post pictures.
    If you break up the circuit so each resistor has a 30 amp fuse. Then If something should go wrong with one the others will still be used as a dump load.
     

    Attached Files:

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