Chapter 9—Disturbance Monitoring 63230-300-212
About Disturbance Monitorin g Ap ril 2001
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Momentary voltagedisturbances are an increasing concern for industrial
plants,hospitals, data centers, and other commercial facilitiesbecause
modern equipmentused in those facilities tends to be more sensitive to
voltagesags, swells, and momentary interruptions. The circuitmonitor can
detect theseevents by continuously monitoring and recordingcurrent and
voltageinformation on all metered channels. Usingthis information, you can
diagnoseequipment problems resulting from voltage sags or swellsand
identifyareas of vulnerability, enablingyou to take corrective action.
The interruptionof an industrial process because ofan abnormal voltage
conditioncan result in substantial costs,whi chmanifest themselves in many
ways:
•labor costsfor cleanup and restart
•lost productivity
•damaged productor reduced product quality
•deliverydelays and user dissatisfaction
The entire processcan depend on the sensitivity of a single piece of
equipment.Relays, contactors, adjustable speed drives,programmable
controllers,PCs, and data communication networks are all susceptibleto
transientand short-duration power problems. After the electricalsystem is
interrupted orshut down, determining the cause may be difficult.
Severaltypes of voltage disturbancesare possible, each potentially having a
differentorigin and requiring a separate solution. A momentary interruption
occurswhen a pr otectivedevice interrupts the circuit that feedsa facility.
Swells and overvoltagescan damage equipment or cause motors to
overheat.Perhaps the biggest power quality problemis the momentary
voltagesag caused by faults on remote circuits.
ABOUT DISTURBANCE MONITORING