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        Discussion Help - Fire on Seaplane - ESC running HOT

#1 J-Bird 662 Mar 19, 2009 02:54 AM

Help - Fire on Seaplane - ESC running HOT
I'm kidding about the fire :D but i'm concerned foam may start melting.

Im running a LSSPJ with a Pentium 30, 2100 mAh Thunder Power 3S, 15C battery in a Polaris seaplane and its running hot. Im not vented and even when running at half throttle the ESC gets too hot to hold for very long although I have not had a thermal shutdown. I may have to install vents but Im curious if perhaps a Pentium 40 might run cooler. Since the ESC is located in a compartment that water can get into - I would prefer not installing the vents.

Any ideas would be appreciated.


#2 The Don Mar 19, 2009 05:42 PM

Any idea of how many amps you are using, how many servos?


#3 J-Bird 662 Mar 20, 2009 12:14 AM

4 Attachment(s)
I can't tell you how many amp as I don't have a watt meter - yet. Ill see if I can find someone to get a current reading on it. I'm using 4 HS 65s for servos. I think I'm getting about 10 min of flight time out of the 2100mAh. The Polaris flys really nice and using the programming card makes reprogramming the Pentium ESC's a breeze.

I hope that helps,

#4 The Don Mar 20, 2009 12:29 AM

My guess is that part of the heat may be from the BEC since you have 4 servos. The BEC is probably working hard to run all four so gets hot. Going to a Pentium 40 will definitely help that as it has s 3 amp switching BEC instead of the 2 amp linear BEC that the pentium 30 has.

VERY nice looking model!


#5 J-Bird 662 Mar 20, 2009 01:01 AM

Thanks Don,

How can I test this - Can I plug in a Battery and let it sit around possibly with the motor running slow?

I'm glad I ran into this problem now as I was going to order 2 other Pentium 30s today and now I may need 3 40s. Do you have them in stock Don?

#6 The Don Mar 20, 2009 06:22 AM

Just sitting does not tell you anything becasue the servos are not moving. You would need to plug the ESC in and wiht no throttle move the sticks all around as if you were flying, then check the temp to see how hot it is getting. As far as stock I have a bunch of 40 amp ESCs in stock right now.


#7 Spid Mar 20, 2009 07:27 AM


I had the same issue going on with one of my models running 4 servos. I switched from the 30A to 40A pentium ESC and the heat issue went away. I agree with Don and believe the Pentium 40A with it's 3A switching BEC will do the trick for you, it did for me.

Best of luck to you and very nice plane you have there!

#8 J-Bird 662 Mar 20, 2009 10:18 AM

Thanks Spid, I'll have them on order today.


#9 J-Bird 662 Apr 01, 2009 10:35 PM

Just to follow up - The Pentium 40 worked great!

Thanks Don,


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