GE Multilin 850

4–108 850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
PROTECTION CHAPTER 4: SETPOINTS
Protection
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
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)
Setpoints
Device
System
Inputs
Outputs
Protection
Monitoring
Control
FlexLogic
Data Capture
Level 1 Level 2 Level 3 Level 4
Power
Frequency
Voltage
Current
Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Testing
Undercurrent
Admittance