temp danger zone?

[steveo]

i know there a general rule of thumb on temps for motor esc and batts- could some one give me an idea- i am doing some testing and have forgot

[Make-a-Wake]

If you dont have a temp gun you can use the 5 second rule. If you can hold your finger on an item for 5 seconds without having to pull away from the heat you are ok. I find that the 5 second rule is around 130-135*..............i dont like to be over that.

[steveo]

i have a temp gun looking for some numbers to stay clear of for all components-

[Make-a-Wake]

135* + is above the zone i like to be in...................

[Fluid]

The biggest problem with measuring temperatures is that many items can cool off fast. An ESC can lose 50*F or more in two minutes; motors and packs will retain their temps a little longer. If you want useful temperature readings, take them as soon as you can after the boat stops. Readings on the ESC can be different on the caps and on the board.

Logged temps on an ICE100 in a P-L Sport Hydro; temp dropped ~60*F in two minutes.
These are internal temps, which are usually higher than external readings from a heat gun.



Average maximum temperatures to avoid damage:
Motor - 160*F
ESC - 150*F
Packs - 140*F

The above are maximums, it is better to be lower as M-a-W stated. Exceeding those temps will not guarantee a meltdown, but the risk of damage is much higher. Over-temping a motor will cause the magnets to lose strength, reducing motor efficiency dramatically.
The result of running a motor with damaged magnets can be a blown ESC - don't ask me how I know that.


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[sailr]

Good info Fluid but I have found that temps can RISE after the run because there is no longer any water running through to cool the motor/esc. If you are running quality equipment, 145 degrees is acceptable to me. Over that, I start reducing props, etc.

I like to read the temps on the caps on the esc, wires end on the motor, and wires end on the batts for my temps. I will check other locations also but those seem to be the hottest.

Totally agree about the magnets taking out an esc! Ask me too!

[Fluid]

Jim, there is no doubt that the ESC cools down the moment the boat stops, look at the graph - I have dozens which all show the same trend. Once the boat stops the motor or ESC no longer generate heat, it cannot get hotter (although the heat can migrate from one point to another). Ditto the packs, when they stop putting out power they no longer create heat. Again the internal temp will drop as the heat moves to the surface of the packs. IME by the time it takes to bring the boat to the bench, untape and measure the temps on the surface of the motor and packs, their temps have already begun to drop.


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[sailr]

Interesting. The graph doesn't lie. I can tell you, however, that I have temped immediately after running and then again a couple of minutes later and the temps are higher. Go figure. Agree totally about the packs.