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Brushless motor and ESC

Discussion in 'Sensors and Actuators' started by Mohamed410, Aug 28, 2014.

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  1. Mohamed410

    Mohamed410

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    Aug 28, 2014
    hello , it's my first time posting here and i hope i have help

    i have a brushless motor with ESC rated as 30 A max

    i tried to connect it to a 12V- 125 A power supply but the ESC was burnt

    i wonder why did this happen ? i was told that the ESC will take the current it needs from the power supply and there are no problem to connect them together

    can anyone explain what happened to me?
     
  2. KMoffett

    KMoffett

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    Jan 21, 2009
    A link to the motor and ESC?

    Ken
     
    davenn likes this.
  3. Mohamed410

    Mohamed410

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    Aug 28, 2014
  4. KMoffett

    KMoffett

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    Last edited: Aug 28, 2014
  5. shrtrnd

    shrtrnd

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    Sometimes I don't know whether to state the obvious because it's remedial information or not. We don't know how much background people have when they ask questions.
    1) Brushless motors are DC. An ESC is generally a DC to 3-phase inverter. Did you apply AC or DC to the ESC?
    2) I don't THINK you'd need an ESC to drive your 'brushless' motor, unless it had brushes, and could run on DC or AC(?)
    2) Was the power supply capable of handling the load? Is it possible the ESC blew because it was trying to draw more current than the power supply could provide?
    Just things I wonder about, that you might want to check.
     
  6. Mohamed410

    Mohamed410

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    Aug 28, 2014
    i put links above for the specifications for both the motor and ESC

    my friend told me he connected it before with the power supply and it was fine

    the power supply gives 12 V which the motor and ESC need but the current rated on the power supply is too high

    its 125 A and the maximum current is 30 for the ESC and i was told that the ESC will take the current it needs from the power supply and not all the 125 A will go into the ESC like what happened and burn it

    also no signal was given to the ESC when this happened , just connected it and then it gave me smoke
     
  7. Gryd3

    Gryd3

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    Jun 25, 2014
    This is 99% true.
    Some cheap power supplies (like the big old wall-warts) are not regulated, so if the device is not pulling any/enough current, the supplied voltage could be higher than expected. This is not very common and would not be the problem in this case.
    Otherwise the device will only pull as much current as it needs. No more, no less. What is important is the voltage of the supply must match the voltage of the device. You must also match polarity (+/-) and type (DC/AC). If you don't pick a proper source you can fry things. The source is allowed to be capable of higher current than you require, and is almost always recommended.
    You may need to contact customer support if the unit was faulty. If you hooked it up wrong, be prepared to buy a new one.
     
    Mohamed410 likes this.
  8. Mohamed410

    Mohamed410

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    Aug 28, 2014

    my friend said he was using it before and it was okay and using it with the same power supply unit and worked fine
    but my programming to the ESC is different from his programming

    he bought the ESC armed but i reprogrammed it and it has to be armed every time also when i used it with the battery it worked fine

    i am really afraid to use another one with the Power supply , i am working now on battery 12 V 10 A which is not sufficient to make it reach maximum current but that's all i got for now , i am still confused
     
  9. Gryd3

    Gryd3

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    Jun 25, 2014
    You may need to read up on the programming. Your friend may be able to point something out quicker than us, as he has experience with that model. I can only look at documents and specs for the product to double check your work.
     
    Mohamed410 likes this.
  10. Mohamed410

    Mohamed410

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    Aug 28, 2014
    unfortunately he couldn't that's why i came here
    and thanks all for your help and interest

    but can the programming in any way be the reason why the ESC was burnt , although the same programming worked fine with the small battery and didn't burn it ?
     
  11. Gryd3

    Gryd3

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    Jun 25, 2014
    Freak accident perhaps.
    A small 12V battery and a large 12V battery should not be the difference in frying the ESC.
    Only possible causes if the programming has remained the same could be:
    -that the larger battery has a different voltage rating than expected.
    -that the larger battery was incorrectly connected to the ESC.
    -that the motor was incorrectly connected.

    This is about as far as I can go. You have confirmed it works with a smaller battery
     
    Mohamed410 likes this.
  12. Mohamed410

    Mohamed410

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    Aug 28, 2014
    thanks a lot for help

    from ur words i knew that the current won't burn it in anyway , but the voltage does and as i am sure the voltage was okay in both cases
    and the connections was okay too , may be something wrong happened

    actually i freaked when i saw smoke , may be i connected it wrong
     
  13. KMoffett

    KMoffett

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    Jan 21, 2009
    Mohamed410 likes this.
  14. Mohamed410

    Mohamed410

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    Aug 28, 2014
    yeah as the polarity of the three wires of motor is not necessary
    i was sure about the power supply connection to the ESC

    but no signals were given to the ESC at that time and the ESC burnt very fast
     
  15. KMoffett

    KMoffett

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    Jan 21, 2009
    Unless the ESC has "reverse polarity protection" (no mention of that) , sounds like you had the power supply polarity to the ESC reversed.

    Ken
     
  16. Arouse1973

    Arouse1973 Adam

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    A 125 Amp power supply rated for 12 Volts may give out a much higher voltage if not regulated. This could damage the ESC which probably has a max input voltage of 14.4 Volts. Do you have details of the PSU?
    Just a thought
    Adam
     
  17. steelgoofy

    steelgoofy

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    Oct 15, 2014
  18. Bluejets

    Bluejets

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    Oct 5, 2014
    You really don't have a choice with only 3 leads coming out.
    If there were 6 leads then you could make it either.
    Star would then give low start current and delta high speed.
     
  19. Bluejets

    Bluejets

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    Oct 5, 2014
    He definetely need an ESC.
    This is what produces the 3 phase ac drive to the brushless motor.
     
  20. steelgoofy

    steelgoofy

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    Oct 15, 2014
    Thanks. I've also managed to measure the inductance of the coils of the motor. (Using an Arduino + some basic electronic part basod on this link: http://www.engineersgarage.com/contribution/inductance-meter-using-arduino?page=2)

    My average value for the inductance between 2 phaes is 1,5 H. Is this value could be real? When measuring the inductance between 2 phaes I actually have 8 coils connected in series. The motor is 12 poles.
     
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