Ground wire melt from 3d printer board between main and regulator

Discussion in 'General Electronics Chat' started by DaSFluX, Oct 12, 2017.

  1. DaSFluX

    DaSFluX

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    Nobody can seem to figure out my problem over 3d printer land so im turning to you guys since this is an electrical problem

    Printer: Highly modified Tevo Tarantula
    Board: MKS Base 1.4 http://reprap.org/wiki/MKS_BASE_1.0
    PSU: Stock Tarantula PSU @12v 30a max Suspect Voltage regulator: DC-DC 3A power Step-Down Adjustable Module Buck Converter 24V To 12v 9V 5V 3V (was enclosed in case at time) Stock wire gauge to


    I had a wire catch on fire going to the BLtouch(a touch probe for 3d printer). This happened after a cold boot during the bed heating up. Im gonna say 15 amps but could be wrong. Its probably The irony is i was JUST about to change all thisThe weird thing... it wasnt a short and didnt melt the connector. It was the ground wire going splitting off of the main power cable. There were no arcs or shorts that started this. I checked the connector housing and wires or one hell of a magic trick happened that i can't find. SO, lol, I got a good question/problem for you guys to scratch your head at.

    I took a youtube video but the audio is bad. People are wiring their 12v fans to the main input all the time without problems. So why would adding a touch probe behind a regulator be a problem Everyone is scratching their head at this. I need a expert.

    Diagram of wiring. Where it burned i marked it with 'burn' in small letters using epic MS paint skills(lol).
    [​IMG]

    Video: (audio isnt so great) Audio kind of sucks, skip half way through as it shows the most i think.


    Buck convertor: (maybe I feed it too many amps?)
    https://www.amazon.com/gp/product/B014Y3OT6Y/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1
     
    DaSFluX, Oct 12, 2017
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  2. DaSFluX

    dorke

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    Yes,
    This is a current thing.
    The burnt wire carried to much current for it to handle.
    The way you wired things isn't desirable.

    Can you solder?
    If you can, solder all the wires together and connect them all at the PSU output(star connection),see below.
    Connected different gauge un-soldered wires with screws at a terminal block isn't a good practice.

    BTW
    ,use AWG18 for 15A.

    Fire_Wire_Example.png
     
    dorke, Oct 12, 2017
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  3. DaSFluX

    turbogt16v

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    If it still burnes wire after above wire scheme,
    Use mobile charger 12v to power fan separately.
     
    turbogt16v, Oct 13, 2017
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  4. DaSFluX

    dorke

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    Can you show on the picture which wire burns and what AWG it is?
     
    dorke, Oct 14, 2017
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