9.2.8 Technical dataTable 216:SAPTOF (81) technical dataFunction Range or value AccuracyOperate value, pickup function (35.00-75.00) Hz ± 2.0 mHz atsymmetrical three-phase voltageReset ratio >0.999 -Operate time, pickup function At 50 Hz: 200 ms typically at fset -0.5 Hz to fset+0.5 HzAt 60 Hz: 170 ms typically at fset -0.5 Hz to fset+0.5 Hz-Reset time, pickup function At 50 and 60 Hz: 55 ms typically at fset +0.5 Hzto fset-0.5 Hz-Timer (0.000-60.000)s <250 ms9.3 Rate-of-change frequency protection SAPFRC (81)9.3.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberRate-of-change frequency protection SAPFRCdf/dt ><SYMBOL-N V1 EN819.3.2 FunctionalityThe rate-of-change frequency protection function SAPFRC (81) gives an early indicationof a main disturbance in the system. SAPFRC (81) measures frequency with highaccuracy, and can be used for generation shedding, load shedding and remedial actionschemes. SAPFRC (81) can discriminate between a positive or negative change offrequency. A definite time delay is provided for operate.SAPFRC (81) is provided with an undervoltage blocking.1MRK 506 335-UUS A Section 9Frequency protection325Technical manual
