Home Products Predictive Maintenance Operation

PMM: Operation

Alarms

There are 4 alarm parameters:

  • Line Change (unexpected change in incoming power)
  • Load Change (unexpected change in process)
  • Existing Faults
  • Developing Faults

Communications

  • RS422/RS485
  • Ethernet (with converter)
  • RS232 (with converter)

Fault detection

PMM training phase

When a fault starts to develop in either the motor or the driven equipment, this has an effect on the output current waveform, making the real system behave differently from the model system. For example, small radial and torsional displacements resulting from an imbalance in a driven fan are transmitted through the coupling to the motor, changing its electrical characteristics in a measurable and repeatable way. This allows the PMM to use the motor as a sensor that can detect faults in both the motor and the driven equipment. 

 

Real time monitoring

PMM operating phase

 

When monitoring, the PMM continuously compares model parameters with those held in the reference model created during the self-training phase. By matching changes in each of these parameters against the equivalent physical characteristic of the motor or driven system and assessing the severity of the change, the PMM determines whether the present condition of the equipment is normal, and if not what action should be taken.This approach not only allows much more sensitive and reliable alerting than is possible with conventional level-alarms, but also recognises the type of defect causing the problem. When monitoring, the PMM continuously compares model parameters with those held in the reference model created during the self-training phase. By matching changes in each of these parameters against the equivalent physical characteristic of the motor or driven system and assessing the severity of the change, the PMM determines whether the present condition of the equipment is normal, and if not what action should be taken.

This approach not only allows much more sensitive and reliable alerting than is possible with conventional level-alarms, but also recognises the type of defect causing the problem.