text: <s>[INST] 1336 Random Faults I have a 25HP 1336 Plus drive that has been faulting out on faults 39,41 and 49 at random intervals. We have checked all of the drive components, motors, contactors etc that are connected to the drive and have found no issues. The drive constantly tries to reset although the Max retries is set to 3. Once power is cycled the drive will run anywhere from 10mins to several days without a fault. Need help [/INST] These faults relate to phase to ground faults between the motor cable and earth.The cable / or motor could have exceeded the corona inception voltage.Is can occur if the motor cables are run in an area where the cable can be immersed in water ( underground conduits )The best way to test this is to disconnect the motor at the motor terminals and start the driveread the current value in parameter 54 ( output current ) any value shown here is what the cable is using.If you meger the cable / motor you need a 1000volt unitYou could turn the carrier frequency PWM ( par 45) down to 2khz / and install a load choke to reduce the reflected wave Read the following tech paper http://www.ab.com/drives/techpapers/ieee/pcic.pdf www.reliance.com/pdf/drives/whitepapers/D7722.pdf \\n </s>