Patent ID: 7572108
Filing Date: 2009-08-11
Classification: F04B,F04D,G05B,G05D,H02H,H02P

Abstract:
1. A method of detecting a fault condition in a motor of a pump, the method comprising: sensing a first bus current value; sensing a speed of the motor; incrementing a counter and setting a timer if the first bus current value is greater than a bus current upper limit and if the speed of the motor is greater than or equal to a high speed limit; attempting to operate the motor in a reverse direction if the counter has been incremented above an increment limit within a first time period; sensing a second bus current value while the motor is operating in the reverse direction; operating the motor in the reverse direction for a second time period if the second bus current value is less than the bus current upper limit and attempting to operate the motor in a forward direction once the second time period has elapsed; and generating a fault condition code and shutting down a drive to the motor if the second bus current value is greater than the bus current upper limit.