Unfortunately, our ROV decided to turn into a thruster eating monster.
We are using T200 thrusters running at 12V controlled by basic ESCs (one of the earlier versions). During the last two weeks we had 4 thrusters breaking down. After checking all the phases we discovered that two phases are broken on all of them (Resistance approx. 1 MOhm). Mechanically the thrusters appear to be in good condition. No corrosion or debris at the stator.
We have replacement thrusters ready to go, but wanted to make sure that we don’t burn through any more thrusters. Has anyone experienced a similar problem or has any idea to what could cause the phases to break?
Our first guess was that the cables are broken. So we cut away one cable, up to the potting, but there was no difference in the resistance measurement. So we assume that the defect must have occured somewhere in the coil. Is it possible that this is caused by vibration or an actuation frequency that is too high?
Thank you for your help,