Schneider Electric 4000 manual 116

Chapter 9—Disturbance Monitoring	63230-300-212
About Disturbance Monitoring	April 2001

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)

116 © 2001 Schneider Electric All Rights Reserved