ORIGINAL: rc flylow
I'm building a ducted fan model and need to extend the leads (12-14 inches) from the 45 amp ESC (Electrifly) to the Ammo in-runner motor driving the fan. (24-45-3790kV) constant current = 25A, maximum surge current = 50A. At 11.1V maximim constant watts = 278. The best wire I can find in the hobby store catalogs is 12ga silicone manufactured in this case by Deans. I use Deans connectors so this seems to be the right wire but I don't find any data showing current ratings. Have I got the right wire for this application? Is there a source somewhere to size and purchase the proper lead wire?Ducted fans will typically physically separate the ESC from the motor and will require longer leads. Thanks for your help!
Good luck with your project.
Check with the maker of the ESC before you do this. Iseem to recall that most ESC makers recommend against extending or modifying the ESCto motor leads. The reason is back EMFsensing.
In order for a brushless ESCto work it has to sense where the rotating parts are so it knows when to switch the various windings on and off.On a brushed motor, this is handled mechancally by the commutator. Ona brushless motor this ishandled by the processor inside the ESC.
On early brushless set-ups they used sensors on the motor to read the position. Later they learned that the spinning components created a "back voltage on the wire" that they could read and use to tell when to switch the power on and off.In order to do this the length of the motor to ESCwire must be known, or so I understand. I am not an electrical engineer, but I seem to recall reading this in one of the ESCinstruction sheets.
So check with the ESCmaker before making any mods to those wires.