Electric motor monitor

A monitor that attaches to and produces an operation history of an ac induction motor, said monitor comprising:

• a structural enclosure;
• a dc power source disposed in said enclosure;
• a flux sensor disposed in said enclosure for sensing magnetic flux generated by the motor, producing a flux signal representing flux;
• a vibration sensor disposed in said enclosure for sensing vibrations generated by the motor, producing a vibration signal representing motor vibrations;
• a motor frame temperature sensor disposed in said enclosure for sensing the temperature of the motor, producing a motor frame temperature signal representing motor frame temperature;
• an ambient temperature sensor positioned external to said enclosure for sensing ambient temperature and producing an ambient temperature signal representing ambient temperature;
• a signal processor disposed in said enclosure for receiving and processing the flux, vibration, motor frame temperature, and ambient temperature signals to produce a plurality of motor operating parameters;
• means for storing the operating parameters, said stored operating parameters corresponding to the operation history of the motor;
• and
• means for outputting at least the stored operating history of the motor.

A method of monitoring an ac induction motor which generates magnetic flux, vibration, and temperature, comprising the steps of:

• attaching an electric motor monitor to the outer frame of an ac induction motor;
• producing a flux signal with said monitor representing magnetic flux generated by the motor;
• producing a vibration signal with said monitor representing vibrations generated by the motor;
• producing a motor frame temperature signal with said monitor representing motor frame temperature;
• processing the flux, vibration, and motor frame temperature signals with said monitor over time to determine a plurality of life history parameters for the motor;
• and
• storing said life history parameters in said monitor.

A system for monitoring the condition of one or more ac machines, the system comprising:

• for each of said one or more ac machines, at least one monitor attached to the machine for sensing and storing a plurality of operating parameters of the machine, said stored parameters corresponding to the operation history of the machine, wherein said at least one monitor includes;
• a structural enclosure;
• an engagement surface formed on said enclosure;
• means for attaching said enclosure to the machine so that said engagement surface is adjacent the machine;
• a power source disposed in said enclosure for supplying dc electrical power to the monitor;
• sensors disposed in said enclosure for sensing a plurality of sensed parameters of the motor and producing a plurality of sensor signals corresponding to the sensed parameters;
• a signal processor disposed in said enclosure for receiving and processing the sensor signals to produce operating parameters of the machine based on the sensed parameters;
• means for storing the operating parameters, said stored operating parameters corresponding to the operation history of the machine;
• and
• means for outputting at least the stored operation history of the machine;
• and
• a portable data collector for downloading the stored operation history of each machine.