GE T60 Instruction Manual page 296

5.4 SYSTEM SETUP
This element responds to frequency rate of change. Separate thresholds are provided for rising and dropping frequency.
The trigger responds to the rate of change of frequency (df/dt) of the phasor measurement unit (PMU) source.
• PMU 1 df/dt TRIGGER RAISE: This setting specifies the pickup threshold for the rate of change of frequency in the
raising direction (positive df/dt). The comparator applies a 4% hysteresis.
• PMU 1 df/dt TRIGGER FALL: This setting specifies the pickup threshold for the rate of change of frequency in the fall-
ing direction (negative df/dt). The comparator applies a 4% hysteresis.
• PMU 1 df/dt TRIGGER PKP TIME: This setting can be used to filter out spurious conditions and avoid unnecessary
triggering of the recorder.
• PMU 1 df/dt TRIGGER DPO TIME: This setting can be used to extend the trigger after the situation returned to nor-
mal. This setting is of particular importance when using the recorder in the forced mode (recording as long as the trig-
gering condition is asserted).
5
5-150 T60 Transformer Protection System
5 SETTINGS
GE Multilin