Instantaneous Torque As Predictive Medicine Tool

On-line testing of motors, diagnostics and motor monitoring have shown large scientific development in the past few years. Current and voltage signature analysis have increased the quality of predictive maintenance (PM) compared to capabilities that RMS current and voltage measurements or power factor readings were able to offer. Signature analysis has progressed from the laboratory stage to become the base for modern instrumentation available to plant personnel. The presently most advanced method of current signature analysis is the torque signal analysis; since it offers dual advantages. On one hand the instantaneous torque signature, gained from current and voltage signatures, is inherently demodulated, delivering a very clear signal that is independent of the line frequency (either 60Hz, or varying in VFD applications). Additional of demodulation, it also delivers the most clear mechanical information available on the motor system, since torque production is the sole reason for the motor's existence. Critical motor or load failures can mean extensive outages or reduced output for weeks at a time in a plant environment.