82 Power Quality Analyzer Model 8230HysteresisHysteresis is a filtering principle, often used after the threshold detection hasoccurred. A correct setting of hysteresis value will avoid repeated triggering whenthe measure is varying close to the threshold.The event detection is activated when the measure is going over the threshold butit can only be deactivated if the measure goes under the threshold minus the valueof the hysteresis.The default hysteresis value is 2% of the reference voltage but it may be set in therange of [1%, 5%] depending of the voltage stability on the system.Detection of voltage overloadHysteresis =2% UrefSwell durationThreshold of swell =100% UrefLevel to go back =100% - 2% = 98% UrefUndervoltage or blackout detectionHysteresis =2% UrefLevel to go back =(100% + 2%)UrefThreshold = 102% UrefDuration
