Can too large an Amp rating be a detriment when choosing an ESC? The plane is a foamy EDF Jet, the recommended battery is a 3S 2200mah LiPoly. Plane originally had a 30A KMS ESC that burned up during low to moderate speed flight. I am considering 45-50A ESC with a factory set cutoff of 3V. Would this be a wise choice for an ESC or overkill?

Thanks,
Ken

There is no problem with buying too large of an ESC.

Ken,

I'm sure others can add more to this as I too am kind of new to electric powered flight.

Its my understanding the required size of the ESC is dependant upon how much the motor draws in AMPS. This is determined by the size of the prop/ducted fan in your choice is turning producing the amount of load. The only way to measure the load is to use an AMP meter to read amount of current draw. Most ESC's will take certain amount of over current draw before overheating and possibly burning up if they don't have thermal protection.

Hope this helps to some extent.

Might not be big enough.
But who knows, the way to tell is to look at what your motor draws at peak. Most mfg's provide that info with their motors.

What motor are you using and how heavy is the plane and........

RCU has a whole set of electric forums. The answer might already be in one of them.

Ken, what you need is one of these, shows Amps, volts, watts, and mah drawn from the pack while testing, only way to set up electric stuff so you won't burn anything up.

Cheers

OK I'm not guru but I do believe that having too large an esc is a bad thing. One of the ESC's functions is to prevent you from burning out your motor. If you over prop a motor it will draw more current than it is rated to handle and since a motor is nothing but coils, metal and magnets there really isn't anything that it will do to shut it's self down when it draws too much current.

When it draws too much current the coils over heat melting the insulation on them thus causing a short circuit. Basically destroying it's self.
The ESC cuts the power to the motor when its max current rating is drawn for a given prolonged period.
Now if the max current your motor can withstand is say 20 amps, your esc is rated at 100 amps and your motor draws 50 amps because you over powered with say a large battery (too many cells) and too large of a prop the ESC will not blow or cut the power to the motor because as fast as it's concerned every thing is fine! however you're motor is way past its limits and will begin to degrade. so YA find some way to find out what you're motors max current draw is find out also what size prop/fan that thing can turn and don't go past that with your ESC.. well that is unless you like fire works!

The plane is a Phase 3 Fantom ARF. The manufacturer installed ESC was a KMS 30A brushless ESC in the plane. Stock prop, stock motor (45-50K rpm.) Hope that helps?

Well, yes. You can't overdrive your engine and expect everything to be fine. To me, that's not really ESC related. You should of course make sure that the higher rated speed controller is indeed enough. That goes without being said.