2 Wire Motor 393 Internal Circuit Breaker?

Frequently after driving our robot which uses 2 “2 Wire Motor 393s” for the drive chassis, the two 393s will freeze up for about 5 seconds, and then driving control will return. While this happens, the other motors on our robot still function. How can we avoid this?


Also, could this have anything to do with the motor stalling?

You need to ensure that the motors have less stress on them at any given time. Stalling the motors will cause their internal breaker to trip very fast, but having a drive train that causes the motors to be constantly pushed very hard (such as gearing the drive 1:3 on a heavier robot or gearing 3:5 on a holonomic base) will cause any minimal amount of stalling to trip the breaker almost immediately.

In other words, you need to change your robot.

That’s weird… we had our robot geared for speed at one point and the breakers tripped, then when we reverted to torque they continued to trip… Our robot weighs approximately 15lbs if that information helps.

You won’t be able to drive a 15 pound robot with only two motors.

Understood… But how come, when we had 4- 2wire 393 motors it wouldn’t drive? We used to be able to drive just fine when we had the old 3-wire motors…

You may have an excess of friction somewhere. Also the 393 motors will trip your breakers. I have tripped the breaker in the old PIC without a Power Expander while using the 3-wire motors, but never on the CORTEX.

Check and try to minimize friction anywhere on your drive would be my suggestion.


i have had the same issue, but 1 of the times i discovered it was due to the 3wire converter taking too much abuse while raising the lift. also i have overheated the 393 motors. This often is a good thing though because it is better than breaking the internal gears which i also have done.

I’ll consider putting two of the drive motors in the 2-wire ports. Thanks!