PROTECTION
Protection
4–108
The 850 protection elements are organized in six (6) identical setpoint groups: Setpoint
Group 1 to Setpoint Group 6.
Figure 4-41: Protection Display Hierarchy
Level 1
Each Setpoint Group has the same protection functions, depending on the relay order
code.
Feeder Elements
•
Undercurrent (37)
Current Elements
•
Inverse Time Overcurrent Curves
•
Percent of Load-To-Trip
•
Phase Time Overcurrent Protection (51P)
•
Phase Instantaneous Overcurrent Protection (50P)
•
Phase Directional Overcurrent Protection (67P)
•
Neutral Time Overcurrent Protection (51N)
•
Neutral Instantaneous Overcurrent Protection (50N)
•
Neutral Directional Overcurrent Protection (67N)
•
Ground Time Overcurrent Protection (51G)
•
Ground Instantaneous Overcurrent Protection (50G)
•
Ground Directional Overcurrent Protection (67G)
•
Sensitive Ground Time Overcurrent Protection (51SG)
•
Sensitive Ground Instantaneous Overcurrent Protection (50SG)
•
Sensitive Ground Directional Overcurrent Protection (67SG)
•
Restricted Ground (Earth) Fault (87G)
•
Switch on to Fault (SOTF)
•
Negative Sequence Time Overcurrent Protection (51_2)
Device
System
Inputs
Group 1
Outputs
Data Capture
Group 2
Protection
Group 3
Monitoring
Group 4
Control
Group 5
FlexLogic
Group 6
Testing
Level 2
Level 3
850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS
Undercurrent
Current
Voltage
Admittance
Power
Frequency
Level 4