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  1. #1
    RC Competitor
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    Esc is running hotter than motor????

    My esc runs at 160. And motor at 97. Why is that. Mamba monster and 2650kv. Battery is 2 2s 40c 5000mah in series.

  2. #2
    RC Turnbuckle Jr. mike-susieq1's Avatar
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    what gearing? gearing plays a role as well. if you gear too high the esc cant handle it but if you gear down too low then it could have the same effect.
    DEU 8:18 ESV

  3. #3
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    21/68. It's really cold out also.

  4. #4
    RC Turnbuckle Jr.
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    part throttle runs create more heat then full throttle runs . the esc sends out full voltage pulses all the time and to run at low speeds cycles it on and off very quickly like 11,000 -13000 times a second!

    A speed controller controls power to the motor by turning full throttle current on and off really fast, 11 to 13 thousand times per second (Pulse Width Modulation or PWM). The percentage of each on/off pulse that is off compared to the part that is on determines how much power the motor sees. I.E. With a pulse that is 50% off and 50% on the motor will see 50% power*. Because each on pulse is 100% of full throttle current, a system set to pull 20 amps at full throttle through a Phoenix 10 will not last if you are throttled back to the point where you only see 10 amps on a wattmeter. The ESC in this case is still switching 20 amps, which it can’t do for long. Actually it is worse than the simple example above. Because an electric motor will always to try to pull as much power as is available to get to its rpm (volts times Kv), when you are running the motor below its Kv speed by switching power on an off, each on pulse will actually be way over the full throttle amp draw. That is why ESCs work harder at partial throttle than full throttle and why we underrate our ESCs. We underrate not so they can handle more current than their rating at full throttle, but so they can handle extended partial throttle operation with no problems.
    Last edited by 50togo; 01-25-2013 at 07:44 PM.

  5. #5
    RC Turnbuckle Jr. mike-susieq1's Avatar
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    I copied this off the forum here for my reference incase i needed it for later use offline.

    Hot motor + cool esc = under geared.
    Cool motor + hot esc = over geared
    Everything warm just right..

    Motor ~ 180/190*F (82/88*C) maximum, ideally 140/160*F (60/71*C), temps can be 10*F higher inside the motor
    ESC ~ pretty much same temps / Fan comes on @ 150*F (65*C)
    Lipo's ~ 140*F (60*C) max, ideally 100/120*F (38/49*C).........
    DEU 8:18 ESV

  6. #6
    RC Turnbuckle Jr.
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    2650kv motor is a little high kv for the maxx also .i was going to say running 21/68 is not overgeared

  7. #7
    RC Turnbuckle Jr. mike-susieq1's Avatar
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    yeah thats what i was thinking but it is a little high since the KV of the motor is higher than the 2200. The 2650kv motor is suppose to have a limit of only 4s so its being at its max there and that gearing is maybe not heating it up but check to see if you gear down to like 17/68 which is stock gearing for a brushless 2200. if temps go down on esc and raise a little on motor then your getting to the right spot if temps dont get too high though.
    DEU 8:18 ESV

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