GE P4A Technical Manual page 8

Contents
Chapter 9 Current Protection Functions
1 Chapter Overview
2 Phase Fault Overcurrent Protection
2.1 POC Implementation
2.2 Directional Element
2.3 POC Logic
3 Negative Sequence Overcurrent Protection
3.1 Negative Sequence Overcurrent Protection Implementation
3.2 Directional Element
3.3 NPSOC Logic
3.4 Application Notes
3.4.1 Setting Guidelines (Current Threshold)
3.4.2 Setting Guidelines (Time Delay)
3.4.3 Setting Guidelines (Directional element)
4 Earth Fault Protection
4.1 Earth Fault Protection Implementation
4.2 IDG Curve
4.3 Directional Element
4.3.1 Residual Voltage Polarisation
4.3.2 Negative Sequence Polarisation
4.4 Earth Fault Protection Logic
4.5 Application Notes
4.5.1 Residual Voltage Polarisation Setting Guidelines
4.5.2 Setting Guidelines (Directional Element)
5 Sensitive Earth Fault Protection
5.1 SEF Protection Implementation
5.2 EPATR B Curve
5.3 Sensitive Earth Fault Protection Logic
5.4 Application Notes
5.4.1 Insulated Systems
5.4.2 Setting Guidelines (Insulated Systems)
6 High Impedance REF
6.1 High Impedance REF Principle
7 Thermal Overload Protection
7.1 Single Time Constant Characteristic
7.2 Dual Time Constant Characteristic
7.3 Thermal Overload Protection Implementation
7.4 Thermal Overload Protection Logic
7.5 Application Notes
7.5.1 Setting Guidelines for Dual Time Constant Characteristic
7.5.2 Setting Guidelines for Single Time Constant Characteristic
8 Broken Conductor Protection
8.1 Broken Conductor Protection Implementation
8.2 Broken Conductor Protection Logic
8.3 Application Notes
8.3.1 Setting Guidelines
Chapter 10 Voltage Protection Functions
1 Chapter Overview
2 Undervoltage Protection
2.1 Undervoltage Protection Implementation
2.2 Undervoltage Protection Logic
2.3 Application Notes
2.3.1 Undervoltage Setting Guidelines
3 Overvoltage Protection
vi
P54A/B/C/E
193
195
196
196
196
198
199
199
199
200
200
200
200
201
202
202
202
203
203
204
205
205
205
205
207
207
207
208
209
209
210
212
212
214
214
214
215
215
215
215
217
219
219
219
219
219
221
223
224
224
225
226
226
227
P54xMED-TM-EN-1