yep 40 and 60 esc's gettong too hot

John LairdJohn Laird Club Members Posts: 3

Running a 40A yep sbec at 30A the heat sink gets very hot. Tried it at 20A - just the same. Thermal cutout came in after about 3 mins.

On same axi 2814/10 motor and 3 lipo setup, tried 30 A on a yep 60A sbec and get the same very hot heat sink.

For comparison, tried a hobbywing Flyfun 60A on a emax BL 2820/07 motor and 3lipo setup and it got hot but nowhere near the heat of the YEPs. YEP esc's set up on factory defaults with timing on auto.

I dont fancy flying a model with these esc's getting this hot. Reviews on the sale pages dont indicate any heat problems.

Any help on this as I dont want to write off 3 esc's as a bad buy??


  • WTWUKWTWUK CornwallClub Members Posts: 13,609 ✭✭✭

    Do you have any airflow over them?

  • John LairdJohn Laird Club Members Posts: 3

    @WTWUK said:
    Do you have any airflow over them

    Yes - for wattmeter checking purposes, battery and esc are in open airstream from the prop, but in model, will be put in a tight space with cooling air entering thru small openings in nose, going over axi motor then past esc/battery. On current heating up, I am doubtful that enough cooling will take place.
    Thanks for comment.

  • WTWUKWTWUK CornwallClub Members Posts: 13,609 ✭✭✭

    Odd. Have used YEP/YGE ESC's (and other identical but differently branded ones) from 18A to 120A in helis for years and given them a hard time when they do get quite warm, but never experienced heat like you are seeing. To get an idea of the heat, can you keep a finger on one for any length of time?

    Do you have the programming card so you can change timings etc. - it could be they don't play well as supplied with that particular motor? I have had that issue with an Emax ESC that got oh my hot with a particular motor that was fine on a HobbyWing Flyfun ESC ...

  • John LairdJohn Laird Club Members Posts: 3

    Thanks for responses - I finally pinned the problem down to ME :censored:

    I got so used to my emax motors on about 1000Kva that I forgot that the AXI which I picked up at a modellers table sale
    had a higher Kva. When I finally got round to checking, the Kva was 1600 and the poor thing was way over propped and that reflected back onto the YEP esc.

    Trawling thru the Power forum , I came across reference to the impact on current load of the Kva which confirmed my conclusions. You can see the reference here


    Reducing the prop from 10 x 6 to 9 x 6 made quite a difference

    As the Bird of Time is not endowed with plenty of space in the nose compartment, I will be adding some scoops to augment the air intakes as the YEP is still running hotter than I am used to. need to order smaller folding props to cool it down further assuming that I still get enough thrust.


  • WTWUKWTWUK CornwallClub Members Posts: 13,609 ✭✭✭

    Yes indeed overpropping can cause Amps to skyrocket. Great that you got a result, as I mentioned I have yet to see a YEP run 'that' hot. They are very good ESC's indeed.

  • Guy BoudreauGuy Boudreau Club Members Posts: 1

    Same problem with my Su-35 push prop. ESC becomes extremely hot and no control on the throttle in the third flight. Need for air flow or bigger ESC?

  • WTWUKWTWUK CornwallClub Members Posts: 13,609 ✭✭✭

    What ESC amperage, battery voltage, motor and prop?

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