Kyle Form 5, Form 5 UDP, Form 5 DC NOVA Recloser Control Installation and Operation Instructions
Directional Sensitive Ground/Earth (SGF/SEF) Fault
The Directional SGF/SEF Fault feature adds directional capabilities to the SGF/SEF protection features. It provides a sensitive ground/earth trip if the fault is downline of the recloser on a radial distribution system. Directional SGF/SEF is used on ungrounded Delta systems for suppression of ground trips for faults occurring on other circuit branches.
The user sets the parameters for Direction SGF/SEF through the interface software via the Protection Profile menu. See Figure 15. In addition to the normal
•Direction Enable
Note: If Direction Enable is not selected, SGF/SEF tripping occurs through normal
•Maximum Torque Angle
•Torque Angle Width (10° to 90°, in 1° increments)
•Zero Sequence Voltage (V0) Threshold (4 to 130 V)
The Maximum Torque Angle parameter determines the angle of maximum tripping sensitivity between the phase angle of the zero sequence voltage and current at the time of fault. The setting of this value depends on knowledge of the power system. Typically, a resistive fault has a value of 0°, and a capacitive fault has a value of 90°.
Torque Angle Width parameter restricts the tripping to an angle of plus or minus the specified width about the Torque angle setting. For example, if the Maximum Torque Angle is 45°, and the Torque Angle Width is set for 10°, then the control will trip at angles between 35° and 55°.
The Zero Sequence Voltage Threshold is used to set the threshold voltage below the disabled directional SGF/SEF tripping voltage.
Note: In most cases, a default value of 4 is adequate.
Directional SGF/SEF Fault is recorded as an event in the control Event Recorder for retrieval. Refer to Service Information
Figure 15.
Directional SGF/SEF configuration screen.
18