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Wires getting hot and insulation melting

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    Wires getting hot and insulation melting

    My wife bought an electric 3-wheeled bike. It is kind of a Pedicab with an electric motor driving the front wheel - and you can also pedal. The bike would be quite a bit heavier than a typical two wheeled bike.

    The controller for the motor is a generic 800W -48V controller. A couple of times now after using the bike for a bit the motor would cut out. I would examine the wiring, which is a bit of a rat's nest and notice that the wires are very hot and it appears that some of the wire insulation has melted at times, shorting out the wires.

    Any idea why this would be happening? Would the controller be trying to push too much current for the size of the wires? Any suggestions on what to do to fix this.

    Here are some pictures:
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    After going for a ride with some uphill sections - it is the green and blue wires coming out of the controller that get very hot. The power wires aren't so hot. What would these wires be? The ones carrying power to the motor? Or do the colors vary with each controller?


    • moarpower
      moarpower commented
      Editing a comment
      They are the phase wires that power the motor (blue, green, yellow.)

      Your controller is rated at 30A/48V peak which equates to ~1500w peak power. So it puts out way more juice than those little phase wires can safely handle.

      I had similar issues on my first build-a "1000w" front wheel kit (48V/30A same as yours) that I put on an old worksman trike and powered with SLA's. It would overheat the phase wires to the point that their coatings melted.

      My trike also "cut out" a few times. The controller was scorching hot and seemed to have gone into thermal shutdown. It would come back on after having cooled off a bit. I added a 48V cooling fan above the controller and all was well in that regard. Ultimately, I scrapped the build because it did not perform well.

      Neither of our rides is a great application for a DD motor-they like to turn at high RPM's and are not very efficient for stop and go, on hills, or for slow speed riding. This is especially true if you have a trike with all that extra weight to carry around. The result of any combination of those factors is that things get hot-the wiring, the controller, and the motor.

      A mid drive setup would ideal allowing you to optimize the motor's performance by changing gears, thereby running your motor in the range where it is most efficient most of the time. This type of system is a bit different in its implementation and upkeep but would be much more suited to your wife's new toy.

      As far as minor modifications that could make a difference, you can upgrade those yellow/blue/green phase wires to a larger size. That would only require basic crimping or soldering skills.

      Changing the controller is not the answer until you upgrade the wiring. Putting more power through wires that are already overheating will only make the problem worse.

    I would eliminate the present set-up and get something with more guts. I see pedicab kits that boast 2000 watts!
    The controller is stamped 'phase angel' so maybe it died and went to heaven already