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Old 10-08-2024 | 04:01 AM
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WingedWarrior64
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Originally Posted by jesse1919
Well, I'm not one to brag but if you insist... I have a MSEE specializing in power electronics and motor drives. I've been working in the aerospace drives industry for 5 years. I'm not exactly a guru but I have worked with several.

That said... I have have nothing to add. LOL Well almost everything's been said but I'll try to clean it up.

1) Inductance from battery to ESC can destroy the ESC especially when you run the ESC at max rated cells (volts). 12 inches max is a good rule of thumb BUT reducing the loop area between the + and - wires is just as important. Twist or tie the wires (loosely) together.

2) Any length from ESC to motor in an RC plane will basically work BUT: [ul]
  • you should still loosely twist/ tie the wires together to reduce radio interference. The three wires act like antennas and placing the three together helps to cancel the fields. Keep them away from antenas and servo wires.
  • you always lose efficiency from resistive (heating) losses in any wire - shorter is better. If you have to go longer, you should use thicker wire. (How big depends and too many things to make a general recommendation)
  • thick long wires are heavy!
    [/ul]

    Jesse

  • Well, let me dig this back up. I’m just trying to get clarification on the inductance from the battery thing. Are you saying that the electromagnetic field generated around the battery wire has the tendency/ability to induce a voltage back into the wire to the ESC potentially spiking the voltage and causing a capacitor to burst? By loosely twisting the wires together are you causing the electromagnetic fields from the positive and the negative wires to cancel out? I would say like a twisted pair but we’re not trying to avoid electromagnetic interference from other components inducing the voltage, right? I’m not building a plane so weight isn’t an issue for me. So would twisted bigger battery wire make a difference here or do I need to stick to short battery longer motor leads? If that’s the case, should the motor leads be braided? And, I haven’t heard anything about reflected voltage issues. Is that even a brushless motor thing or just an industrial 3-phase thing? Can anyone give an answer that includes the science of it? I greatly appreciate all of you.