Overview
The “Restricted ground fault” element provides sensitive ground fault detection for low-magnitude fault currents, primarily faults close to the neutral point of a wye-connected winding. An internal ground fault on an impedance grounded wye winding produces a fault current dependent on the ground impedance value and the fault position on the winding with respect to the neutral point.
For more detailed information on “Restricted ground fault” element, refer to GE, Universal Relay (UR) family of products, Version 8.0x manuals.
To see other supported elements, click here.
Setting Parameters
Modbus memory map for Setting parameters
| Products | Hex address | Register name | Range | Units | Step | Format | Default |
| F60, G30, G60, L90, T35, T60 | 6CF2 | Restricted Ground Fault 1 Function | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | 6CF3 | Restricted Ground Fault 1 Source | 0 to 5 | — | 1 | F167 | 0 (SRC 1) |
| " | 6CF4 | Restricted Ground Fault 1 Pickup | 0.005 to 30 | pu | 0.001 | F001 | 80 |
| " | 6CF5 | Restricted Ground Fault 1 Slope | 0 to 100 | % | 1 | F001 | 40 |
| " | 6CF6 | Restricted Ground Fault 1 Delay | 0 to 600 | s | 0.01 | F001 | 0 |
| " | 6CF7 | Restricted Ground Fault 1 Reset Delay | 0 to 600 | s | 0.01 | F001 | 0 |
| " | 6CF8 | Restricted Ground Fault 1 Block | 0 to 4294967295 | — | 1 | F300 | 0 |
| " | 6CFA | Restricted Ground Fault 1 Target | 0 to 2 | — | 1 | F109 | 0 (Self-reset) |
| " | 6CFB | Restricted Ground Fault 1 Events | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | 6CFC | …Repeated for RGF 2 | |||||
| " | 6D06 | …Repeated for RGF 3 | |||||
| " | 6D10 | …Repeated for RGF 4 | |||||
| T35, T60 | 6D1A | …Repeated for RGF 5 | |||||
| " | 6D24 | …Repeated for RGF 6 |
| F102 | 0 = Disabled, 1 = Enabled | ||||||
| F109 | 0 = Self-reset, 1 = Latched, 2 = Disabled | ||||||
| F167 | 0 = SRC 1, 1 = SRC 2, 2 = SRC 3, 3 = SRC 4, 4 = SRC 5, 5 = SRC 6 | ||||||
Logics & highlights
RGF and percent differential zones of protection
Typical applications of RGF protection
Fault current through transformer neutral against primary current (left is resistance-ground neutral, right is solidly grounded neutral)
Fault current through transformer neutral against primary current (winding current flow during ground fault)
Pickup & slope parameters
Definitions (1)
Definitions (2)
Restricted ground fault logic
Calculation examples
