5-218 F60 Feeder Protection System GE Multilin5.6 GROUPED ELEMENTS 5 SETTINGS5The undervoltage elements can be programmed to have a definite time delay characteristic. The definite time curve oper-ates when the voltage drops below the pickup level for a specified period of time. The time delay is adjustable from 0 to600.00 seconds in steps of 0.01. The undervoltage elements can also be programmed to have an inverse time delay char-acteristic.The undervoltage delay setting defines the family of curves shown below.(EQ 5.28)where: T = operating timeD = undervoltage delay setting (D = 0.00 operates instantaneously)V = secondary voltage applied to the relayVpickup = pickup levelFigure 5–95: INVERSE TIME UNDERVOLTAGE CURVESAt 0% of pickup, the operating time equals the UNDERVOLTAGE DELAY setting.T D1 VV pickup------------------– ----------------------------------=842788A1.CDR% of voltage pickupTime (seconds)NOTE
