3.6 Phase Overcurrent Protection 689
3.6.1 Transient Overreach and Overshoot 690
3.6.2 Phase Overcurrent Directional Parameters 690
3.7 Earth Fault Protection 690
3.7.1 Earth Fault Directional Parameters 690
3.8 Sensitive Earth Fault Protection 691
3.8.1 Sensitive Earth Fault Protection Directional Element 691
3.9 High Impedance Restricted Earth Fault Protection 691
3.10 Negative Sequence Overcurrent Protection 691
3.10.1 NPSOC Directional Parameters 692
3.11 Circuit Breaker Fail and Undercurrent Protection 692
3.12 Broken Conductor Protection 692
3.13 Thermal Overload Protection 692
4 Monitoring, Control and Supervision 693
4.1 Voltage Transformer Supervision 693
4.2 Standard Current Transformer Supervision 693
4.3 Differential Current Transformer Supervision 693
4.4 CB State and Condition Monitoring 693
4.5 PSL Timers 694
5 Measurements and Recording 695
5.1 General 695
5.2 Disturbance Records 695
5.3 Event, Fault and Maintenance Records 695
5.4 Fault Locator 695
6 Ratings 696
6.1 AC Measuring Inputs 696
6.2 Current Transformer Inputs 696
6.3 Voltage Transformer Inputs 696
6.4 Auxiliary Supply Voltage 696
6.5 Nominal Burden 697
6.6 Power Supply Interruption 697
6.7 Battery Backup 698
7 Input / Output Connections 699
7.1 Isolated Digital Inputs 699
7.1.1 Nominal Pickup and Reset Thresholds 699
7.2 Standard Output Contacts 699
7.3 High Break Output Contacts 700
7.4 Watchdog Contacts 700
8 Mechanical Specifications 701
8.1 Physical Parameters 701
8.2 Enclosure Protection 701
8.3 Mechanical Robustness 701
8.4 Transit Packaging Performance 701
9 Type Tests 702
9.1 Insulation 702
9.2 Creepage Distances and Clearances 702
9.3 High Voltage (Dielectric) Withstand 702
9.4 Impulse Voltage Withstand Test 702
10 Environmental Conditions 703
10.1 Ambient Temperature Range 703
10.2 Temperature Endurance Test 703
10.3 Ambient Humidity Range 703
10.4 Corrosive Environments 703
11 Electromagnetic Compatibility 704
11.1 1 MHz Burst High Frequency Disturbance Test 704
11.2 Damped Oscillatory Test 704
11.3 Immunity to Electrostatic Discharge 704
Contents P446SV
xx P446SV-TM-EN-1
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