Euan Galloway wrote:Andy,
looking good mate, can i ask if you have run up the motor yet? and if so how many watts and amps?? also i have smoked two of the 200 amp esc in the last couple of weeks<one at only 67 amps?> and the other when i powered it up?,
cheers Euan,ps lucky i bought them in the UK not HK as i have got my cash back.
Hi Euan,
Thanks for the comments. I have run each motor and its corresponding esc with no load, run both motors together with no load and run both with a 30"x20" prop to approx half throttle....at which point Sam was being pulled across the driveway. My main concern has been to do with running 2 esc's together
I have also read of quite a few other of these 200amp esc's having burnt out as well. It may well be that there is just a fault with some of them.
I have another of these 200amp escs. We have been flying an LMA Genesis with a 200amp esc on it and it has behaved perfectly. I haven't measured its current because my ammeter only went to 100amps (but I have just bought another shunt so can do 200amps now!). I do know that it was taking way more than 200 because it would cut out. We had to set our throttle end point at 15% on the top half travel!
I have run quite a number of large motor and esc's. It is very importannt with big motors to get the timing of the esc set correctly for the corresponding number of windings in the motor. Small motors are essentially single windings ie its 3 phase and there are 3 windings. Larger motors can have more windings. I think the ones I am using in this plane has 12, so since it is 3 phase still it has the equivalent of 4 coils per phase. This means the timing can be 1/4 of that used for a single wound motor.
The escs we use for our model motors are very simple 3 phase motor drives. There is no position detection on the motor so the esc decides where the rotor is in relation to the magnets by sensing the resistance in each phase. If the timing is not matched then the motor can get into trouble. Have you ever wacked full throttle on and got a very loud screech from a motor? This is when the current being applied to a winding is slightly out of time and ends up trying to turn the motor backwards - you get one winding trying to drive the motor one way and another trying
to drive it the other way.
If the esc phases are 'fighting' each other then although the actual forward driving current may be say 67amps as you had, the current in a phase may be much higher and hence damage some of the FETs in the esc.
What have you been using with your esc's?
Cheers, Andy
......I suppose the good side of it was that I was on my way back to the house when my back completely went though 
