I suspect some of you flying bigger electric seaplanes (10 lb. and more) have experienced heating problems with high voltage ESCs (temperature auto cut-off, burning, etc.).
I had major failures on 2 of my seaplanes last week end at a float fly in Quebec because of heating ESCs... A Sig Kadet Senior on floats and a Great Planes Seawind (both around 11 lb.). One ESC fried and the other auto heating cut-offed, both after about 3 minutes in the air.
These were maiden flights...
The Kadet had a Monster Power 60, 2x3600 30c 6s lipos, 15x8 prop and a 100a K Force ESC. The amp draw during testing was 70a at full throttle (but much less during the actual flight).
The Seawind had a Rimfire 60, a 3-blade 13x8 MAS and with that motor the amp draw was more than 90a! We had to lower the end point of the throttle stick to achieve the desired amps at around 70. During the flight the ESC first cut-offed so the plane could be landed safely. But it fried moments later..
I thought a 100a ESC would handle an average of 60 amps even with no airflow... But I was wrong.
The other "big" seaplane I had was a 12lb. Canadair CL-215 (2xPower 46, 2x5000 25c 4s lipos, 2 x 14x7 MAS 3-blade and 2xTurigy Plush 60a ESCs). No heating problem in 5 flights.
It seems smaller ESCs (30-60a) can handle proportionally more amps without airflow. Am I right?
Now, I guess I will need to put a cooling fan on my high voltage ESCs...
I know these fans do exist but the only cooling fans I found were for car ESCs... Will they work on airplanes?
Or should I put a 120 or a 200a ESC to be safe??
Any help would be appreciated.