FAULT DIAGNOSIS APPARATUS FOR ELECTRIC PUMP

摘要

PROBLEM TO BE SOLVED: To prevent an erroneous determination that a normal electric pump has a fault, by making a diagnosis considering a factor having an effect on fault diagnosis, in a fault diagnosis apparatus for an electric pump.SOLUTION: After an electric pump is activated, when a motor is driven with a current of the driving motor before a predetermined time T1 passes by defining an upper limit current I which is used in a normal state as a current limit value, it is determined that there is a possibility that a fault occurs in the pump when a rotation frequency of the motor is less than a lower limit of rotation frequency determined according to a temperature condition (a lower limit temperature) of hydraulic oil, and the determination is reported to an external device. When the motor is driven by limiting the current of the motor after T1 passes to I and I(I), it is determined that there is a possibility of a fault when rotation of the motor stops, and the determination is reported to the external device.