HVJB Deep Dive: Is there any way that software fixes the problem of overheating contactors?

zippy

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So I watched that whole John Kelly vid. Makes me think that the four big contactors failing are just the symptoms. Welded shut seems like too much current. its the Amps that'll kill ya. And the section he describes "sequence"...milliseconds really, could something be off in timing? letting too much juice through, for a millisecond? Both stomping pedal 5 times fast, outside contacts or DC fast charge, inside contacts, can make it happen?
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Fixbear

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So I watched that whole John Kelly vid. Makes me think that the four big contactors failing are just the symptoms. Welded shut seems like too much current. its the Amps that'll kill ya. And the section he describes "sequence"...milliseconds really, could something be off in timing? letting too much juice through, for a millisecond? Both stomping pedal 5 times fast, outside contacts or DC fast charge, inside contacts, can make it happen?
Timing does matter because they use a smaller contactor and resistor to charge the large capacitors in the motors. Without the resistor the capacitors are capable of drawing well over a 1000 amps. Once they are charged, then the main contactors close and the car is ready.
By using capacitors at the motor, they can reduce the size of the conductors to the motors, the contactor capacity, and help control the battery flow. The capacitor can also provide power in reverse. So timing of the auxiliary contactor is very critical to prevent arcing. Most contact damage is done at opening at first. Then as the surface gets eroded, it increases resistance. Thus making heat and possible damage. There are so many variables, It's a good bet that the Ford electrical engineers are working hard even now to fully understand what's happening. Even after all the changes they have made.
 
 




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