Submerged, drilled, bored, depth differences will have different setups and sizes.
But to run several cycles then trip random makes believe the pump is getting bad. A short for something fairly static doesn't come and go. Now if the pump is kicking some because the arrestor devices are missing or broke (smaller diameter drilled well) I could see it wiggling and banging off the casing.
Me thinks if it's a nine out of ten deal the motor in rush current is over loading the circuit. Do you have a meter that will measure amps or load? Run them critters a bunch of water and try to catch a spike on start up?
