What happens when you overload your BEC/ESC ? - RC Groups
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Jun 07, 2002, 07:18 AM
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RonJ's Avatar

What happens when you overload your BEC/ESC ?

Installed a 3:1 geared Endo and 11 x 6.5 folder on my stress reinforced Dymond Crazee. With 8-2000SCR's it pulled 47 amps on the ground. I have a 50 amp BEC/ESC. Launches great but after seconds in the air the servos lock to full up and right aileron. I cut the throttle and control is returned but the plane stalls. To recover from the stall I hit the throttle and control is lost again. This has resulted in losing two wing panels, two fuselages, and some grey hair on the back of my head. Range checks perfect before and after crashes.
Does an unloaded prop draw more amps which overloads the BEC/ESC ? HELP
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Jun 07, 2002, 09:45 AM
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Andy W's Avatar
No, in-flight loads are lower than static (unless, perhaps, in extreme circumstances). You are well within operating limits, although not all 50A esc's are created equal. It may, however,be interference, not an overload condition, but it's hard to tell..
Jun 07, 2002, 10:38 AM
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Jim Ryan's Avatar
If you're losing control that quickly, I believe this points to an interference problem as Andy noted. Even if you exceed limits on a BEC-type ESC, it will typically take a little time for the components to overheat.

BTW, it's worth noting that there are a couple of ways to induce failure in a BEC ESC. The first is to draw too much current on the motor side, thereby overheating the FETs. The other way is to draw too much current through the voltage regulator that's the heart of the BEC; if you use too many servos, or those servos are subjected to heavy loads, you might overheat the voltage regulator, causing it to fail.

Since you're regaining control as soon as you cut power to the motor, it's very unlikely that this is your problem.

I suggest you range check the plane, but this time with the motor running at various power settings. It may be that you need more noise suppression. Another option on a plane this size is that you could switch to an opto-isolated ESC and use a separate receiver battery.