Ground Directional - GE 489 Instruction Manual

4 SETPOINT PROGRAMMING
T

GROUND DIRECTIONAL

T
[ENTER] for more
The 489 detects ground directional by using two measurement quantities: V
determines if a ground fault is within the generator or not. This function should be coordinated with the 59GN element (95%
stator ground protection) to ensure proper operation of the element. Particularly, this element should be faster. This ele-
ment must use a core balance CT to derive the I
blocked for neutral voltages, V
The pickup level for the ground current elements is programmable as a multiple of the CT. The 50:0.025 CT is
intended for very sensitive detection of ground faults and its nominal CT rating for the 489 is 50:0.025.
NOTE
For example, if the ground CT is 50:0.025, a pickup of 0.20 would be 0.20 x 5 = 1 A primary. If the ground CT is 50:0.025, a
pickup of 0.05 would be 0.05 x 5 = 0.25 A primary. Refer to Appendix B for Application Notes.
GE Power Management
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SUPERVISE WITH
ENTER
DIGITAL INPUTS: Yes
ESCAPE
GROUND DIRECTIONAL
ESCAPE
MTA: 0°
MESSAGE
GROUND DIRECTIONAL
ESCAPE
ALARM: Off
MESSAGE
ASSIGN ALARM
ESCAPE
RELAYS (2-5): ---5
MESSAGE
GROUND DIR. ALARM
ESCAPE
PICKUP: 0.05 x CT
MESSAGE
GROUND DIR. ALARM
ESCAPE
DELAY: 3.0 sec.
MESSAGE
GROUND DIR. ALARM
ESCAPE
EVENTS: Off
MESSAGE
GROUND DIRECTIONAL
ESCAPE
TRIP: Off
MESSAGE
ASSIGN TRIP
ESCAPE
RELAYS (1-4): 1---
MESSAGE
GROUND DIR. TRIP
ESCAPE
PICKUP: 0.05 x CT
MESSAGE
GROUND DIR. TRIP
ESCAPE
DELAY: 3.0 sec.
MESSAGE
signal. Polarity is critical in this element. The protection element is
0
, below 2.0 V secondary. Refer to the APPLICATION NOTES for more details.
0
489 Generator Management Relay
4.6 S5 CURRENT ELEMENTS
4.6.9 GROUND DIRECTIONAL
Range: Yes, No. Seen only if a digital input is assigned to
Ground Switch Status
Range: 0°, 90°, 180°, 270°
Note: MTA = Maximum Torque Angle
Range: Off, Latched, Unlatched
Range: Any combination of Relays 2 to 5
Range: 0.05 to 20.00 × CT in steps of 0.01
Range: 0.1 to 120.0 sec. in steps of 0.1
Range: On, Off
Range: Off, Latched, Unlatched
Range: Any combination of Relays 1 to 4
Range: 0.05 to 20.00 × CT in steps of 0.01
Range: 0.1 to 120.0 sec. in steps of 0.1
and I . The angle between these quantities
0 0
4
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