fans for cooling??

[jjrctech]

has anyone ever try to run fans to cool the motor and esc ?? becuase I was thinkingto run the boat cat c5000 on saltwater and did not want the saltwater on the motors

do fan work well or not ?? any wone have a setup like this?

Thanks

[6sHyper]

I've seen a few peopel do it and they said it worked, but my general thought was theres no fresh cool air to draw from to get the most efficiency out of it, you know another idea if you dont want salt on the motors would to be to use Outrunner motors?? I've even heard someone say the big outrunners can circulate enough air to cool an esc if you put it close enough.

[m4a1usr]

Its been my experience that with shorter endurance boat runs, air works at least as well as any water cooling method will. First the obvious. The trapped air inside a hull is ambient. So if its cool outside, then the air circulating will be at first. Second, typical run times for most of us are several minutes long. Maybe what? 3 or 4, maybe 5 minutes but thats not typical. Some are shorter. 2 minutes.

I actualy like my speed controllers to have a fan blowing down on the heat sink. Car controllers do it and survive quite well. And they get dusty! That acts like an insulator. Water cooling an ESC is a simple, yet practical way to remove heat. If the heat transfer media is efficient you probably get the greatest btu heat removal in a given amount of time with water cooling. But the problem is FETS get hot fast. They put enough heat into any heat sink far faster then it can be removed by either water or air. So no matter what method you choose the typical speed controller will over heat and shut down given a long enough time frame when running.

Air has been proven to work and it does. But so does water. In your case I can see why you dont want to expose the motor and speed controller to salt water. I dont even like to expose my hardware to a corrosive enviornment. Thats not to say dont do it. Its just each of our own preferences.

Now I am a critic of depending on water cooling a motor. Why? Because if you sized it correctly to begin with it would not over heat requiring any cooling. That doesnt mean I do not water cool some of my motors. But think about what you are cooling with a jacket. The rotor? No. The stator iron? No. The aluminum shell and some of the windings closest to the motors exterior. Yes. Water jackets do not cool the most important items of an electric motor. A hot rotor has less magnetism. Hot iron has less attraction. True,......cooler copper has less IR but thats the very reason to size your motor appropriately.

Dont take my opinion as critism. Its not meant that way. I would like to see more folks grabble with the bigger problems like prop choices, tuning and battery choices. Just my 2 cents for what its worth.



John

[Diesel6401]

http://forums.offshoreelectrics.com/...32&postcount=8

http://forums.offshoreelectrics.com/...35&postcount=9

[Fluid]

For short run times even in hot weather, a fan can cool an ESC well enough to keep it from getting too hot. It needs several things though:

- The ESC has to be sized correctly for the boat. Trying to run a 60 amp ESC in a 120 amp draw setup is asking for trouble no matter what.

- The hull has to have a decent volume of air in it. A rigger is a poor choice, a typical cat is a good one. Sport hydros are in the middle.

- Run times over three minutes in hot (90F+) weather can result in high ESC temps. But in summer the water temp is ofter in the upper 80s so even water cooling does not work so well.

I run a fan-cooled Castle ICE200 with a fan in my 180 amp P Sport Hydro in 90F weather and the ESC never gets close to thermalling in a two minute heat.


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