dangers of running a motor above rated amps

[ezhitz]

I was wondering how hard is it on the motor running it above its max amps?
Running a bj26 motor 1500kv 45 amps in my df29 on a m445 prop its peaking around 78 amps but running between 50-60 amps.I'm using a turnigy 120 amp esc so thats not a problem. Outside temp is cold so after 6 minutes of running everything is just warm.Boats running upper 30's on that prop but I don't want to kill the motor if the amp draw is to high.If I thin the prop more and bar cut could maybe lower the amp draw.
Thanks Jack

[Fluid]

That is a difficult question to anwer. High amp draw increases heat, moreso on motors which are not high-amp designs to begin with. Any motor will eventually reach core saturation, after which most all energy is converted to heat rather than to rotational energy.

What is safe to do? From personal experience, the UL-1 and BJ26 motors can withstand 80 to 90 amp average draws for two minutes - as long as the motor doesn't get too hot. Too hot probably means over 150*F with these motors. Larger Neu motors on the other hand can use upwards of 300 amps successfully, some don't even reach their maximum efficiency until 250 amps. They can withstand 185*F or higher.


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[ray schrauwen]

Cool

[ezhitz]

Thanks Fluid thats good to know so far the motor has only been warm to the touch.I do think with some prop work i can lower the average amp draw.