To accurately calculate the remaining life of the winding of a motor by calculating the remaining life by reflecting the difference between the temperature of the motor obtained from multiple protector relays and the highest allowable temperature in the cumulative operating time of the motor.
Multiple protector relays (IPMAT) 2 connected to a motor 1 transmit input information required for calculating the remaining life of the winding of the motor 1 to a computer 3 through a transmission system under the control of a transmission controller 4. The input information includes such contact information as 'stopping', 'operating', etc., and such measured information as 'motor temperature', 'highest allowable temperature', 'operating time', etc. In addition, 'designed life', 'ambient temperature', 'reference value', etc., as inputted to the computer 3 as set information. The computer 3 is made to calculate the remaining life of the winding against the designed life by reflecting the difference between the temperature of the motor 1 obtained from the relays 2 and the highest allowable temperature in the cumulative operating time of the motor 1. Therefore, the remaining life of the winding can be calculated by accurately deciding the degree of deterioration of the winding which varies depending upon the loaded condition of the motor 1.
HORIUCHI TAKANORI
SANADA YOSHIHARU
MOCHIZUKI NOBUKAZU
