Chapter 9—Disturbance Monitoring 63230-300-212
About Disturbance Monitoring April 2001
© 2001 Schneider Electric All Rights Reserved
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With the information obtained from the circuit monitor during a disturbance,
you can solve disturbance-related problems, including the following:
• Obtain accurate measurement from your power system
— Identify the number of sags, swells, or interruptions for evaluation
— Determine the source (user or utility) of sags or swells
— Accurately distinguish between sags and interruptions, with accurate
recording of the time and date of the occurrence
— Provide accurate data in equipment specification (ride-through, etc.)
• Determine equipment sensitivity
— Compare equipment sensitivity of different brands (contactor dropout,
drive sensitivity, etc.)
— Diagnose mysterious events such as equipment failure, contactor
dropout, computer glitches, etc.
— Compare actual sensitivity of equipment to published standards
— Use waveform capture to determine exact disturbance characteristics
to compare with equipment sensitivity
— Justify purchase of power conditioning equipment
— Distinguish between equipment failures and power system related
problems
• Develop disturbance prevention methods
— Develop solutions to voltage sensitivity-based problems using actual
data
• Work with the utility
— Discuss protection practices with the serving utility and negotiate
suitable changes to shorten the duration of potential sags (reduce
interruption time delays on protective devices)
— Work with the utility to provide alternate “stiffer” services (alternate
design practices)
