How hot is too hot - motor + controller

Obviously a super hot controller/motor is not a good thing, but how hot is too hot? I’ve searched around but have yet to read anything with specifics. I’m just wondering how hard I can push my components without the controller or motor frying.

I’m currently running a 40 amp controller, but modified the shunt a bit, with a crystalyte TC100.

I put a thermometer prob into my controller to get a sense of the temperature. Obviously the ambient temperature is a factor, but in any case, when I ride my bike in a chill manner, it tends to hover around 110F. When I push it for a bit, it hovers around 140-170F. I’m located in Boston and we’re getting into summer temps that hang around 70-80F.

I have a temp sensor in the motor, which I have connected to a CA3, but I don’t trust the numbers, the seem pretty high, so I’m guessing something isn’t set up properly.

So anyways, that’s my setup, does anyone have either any hard technical resources of what temperature will start to fry things, or even just experience of temps that fry things?

I’m sure it varies significantly depending on specific components, but any kind of ballpark figures would be interesting to hear, or any links to related posts would be appreciated.

Most Chinese motor phases melt somewhere at 130c+ so somewhere around 100c should be your max.
Controller Mosfets fry somewhere around 105c+. Kelly Controllers shut down at 75c case temp or 100c Mosfet

There are threads here on ES somewhere, you just have to look (hard).

Quote from Wikipedia:

The temperature class indicates the temperature of the wire at which it has a 20,000 hour service life. At lower temperatures the service life of the wire is longer (about a factor of 2 for every 10 °C lower temperature). Common temperature classes are 105 °C, 130 °C, 155 °C, 180 °C and 220 °C.

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Authentic Honeywell hall sensors can take a lot of heat, but...I wouldn't heat them to over 200F / 93C. Generic Halls? your guess is as good as mine...

Cheap solder can get soft when it's hot.

"affordable grade" neodymium magnets will permanently lose some of their magnetism.

The lacquer on the wires in the motor coils can bake away and cause a short. If there is one spot on one wire where the lacquer is a little thin already?...it only takes one small short to ruin the motor...

Also, if you are regularly getting your motor and controller up to 200F / 93C, you are wasting a lot of battery watts to simply create waste heat. 160F / 71C is probably when you should be cutting back on the amps, and 140F / 60C is probably better...

My thing is where are you measuring the temperatures? What part of the motor gets the hottest? Stator or rotor?

Philaphlous said:

My thing is where are you measuring the temperatures? What part of the motor gets the hottest? Stator or rotor?

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Obviously the stator in which the copper coil are located