Page 10 - Guard II+ - Use Data Effectively

ON-LINE MONITORING THE EFFICIENT WAY

The What?

The What … Partial Discharge
… because the PD monitoring system uses VHF and time-of-flight to automatically filter out noise and classify
disturbances, then the output of the Guard monitor is only the PD detected by each sensor. As such, the DCS can be
configured to trend (doubling over a twelve-month interval) and when compared to the Iris database issue alerts,
warnings, and notifications. Additionally, the polarity of the PD pulses is tracked individually, so whether the source
is polarity predominant and/or correlates with load or temperature can be determined. This makes it possible to
determine the problem coils and if the problems are likely due to thermal deterioration, coil/bar movement, surface
ti it d t i ti f th t i l ti

The What … Flux
… because the flux monitoring system automatically calculates the difference in flux between coils of
opposite poles in round rotors and the total flux for salient pole rotors, then the output of the Guard
monitor is only these values. As such, the DCS can be configured to trend these values and to issue alerts,
warnings, and notifications. If a synchronization probe is also present, then the problem coil can also be

The What … Endwinding Vibration
… because the endwinding vibration monitoring system automatically calculates the total, radial and tangential
displacement and velocity, then the output of the Guard monitor is only these values. As such, the DCS can be
configured to trend these values and to issue alerts, warnings, and notifications. This makes it possible to
determine where any vibration is occurring and if the vibration correlates with load or temperature variations.

The What … Shaft Voltage and Current
… because the shaft monitoring system automatically calculates the voltage and current of up to 4 sensors
then the output of the Guard monitor is only these values. As such, the DCS can be configured to trend these
values and to issue alerts, warnings, and notifications. This makes it possible to determine if the grounding
brush is adequately functioning to protect the bearing insulation.