Schneider Electric 4000

Chapter 9—Disturbance Monitoring 63230-300-212

About Disturbance Monitorin g Ap ril 2001

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With the informationobtained from the circuit monitor during a disturbance,

you cansolve disturbance-related problems, including thefollowing:

•Obtain accuratemeasurement from your power system

—Identifythe numberof sags, swells, or interruptions for evaluation

—Determine the source(user or utility) of sags or swells

—Accuratelydistinguish between sags and interruptions, with accurate

recordingof the time and date of the occurrence

—Provide accuratedata in equipment specification (ride-through, etc.)

•Determine equipmentsensitivity

—Compareequipment sensitivity of different brands (contactordropout,

drivesensitivity,etc.)

—Diagnose mysteriousevents such as equipment failure, contactor

dropout, computerglitches, etc.

—Compare actual sensitivityof equipment to published standards

—Use waveformcapture to determine exact disturbancecharacteristics

to comparewith equipment sensitivity

—Justifypurchase of power conditioning equipment

—Distinguishbetween equipment failures and power system related

problems

•Developdisturbance prevention methods

—Developsolutions to voltage sensitivity-based problemsusing actual

data

•Work with the utility

—Discuss protectionpractices with the serving utility and negotiate

suitablechanges to shor tenthe duration of potential sags (reduce

interruption time delay s on protective devices)

—Workwith the utility to provide alternate“stiffer”services (alternate

design practices)