ABB REL 356

ABB REL 356 Current Differential Protection
Page vii
Change Detector Supervision ................................................................................................................... 4-5
Open Breaker Function ............................................................................................................................ 4-5
Stub Bus Trip ........................................................................................................................................... 4-5
Weak Feed Trip........................................................................................................................................ 4-6
Reclose Initiate Logic ............................................................................................................................... 4-6
High Set Overcurrent Elements ................................................................................................................ 4-6
Fault Locator ............................................................................................................................................ 4-7
Faulted Phase Selector ............................................................................................................................ 4-7
Differential Protection Disable .................................................................................................................. 4-8
Optional Backup Functions............................................................................................................................. 4-8
Distance Protection .................................................................................................................................. 4-8
Backup Protection Disable ....................................................................................................................... 4-8
Sensitive Directional Ground Overcurrent Unit.......................................................................................... 4-8
Out of Step Trip and Out of Step Block Logic ........................................................................................ 4-12
Loss of Potential (LOPB) ....................................................................................................................... 4-13
Loss of Current Monitoring ..................................................................................................................... 4-13
Section 5 Testing
Introduction .................................................................................................................................................... 5-1
Equipment Needed ......................................................................................................................................... 5-1
Test Setup...................................................................................................................................................... 5-1
Current and Voltage Inputs ....................................................................................................................... 5-1
Analog Input and Front Panel Metering Test ................................................................................................... 5-1
Contact Input Subsystem Test ....................................................................................................................... 5-2
Relay Output Subsystem Test........................................................................................................................ 5-3
Communication Subsystem Test .................................................................................................................... 5-3
9600 bps Audio Tone Option .................................................................................................................... 5-3
56/64 kpbs Digital Communication Option ................................................................................................ 5-3
Functional Tests - Current Differential System ............................................................................................... 5-4
Single Unit Loopback Test - Internal Faults .............................................................................................. 5-5
Single Unit Loopback Test - External Faults............................................................................................. 5-8
Dual Unit Back to Back Test - External Faults ......................................................................................... 5-8
Dual Unit Back to Back Test - Internal Faults .......................................................................................... 5-9
Functional Tests - Optional Backup System ................................................................................................. 5-10
Phase to Ground Units ................................................................................................................................. 5-10
Zone 2 Phase-Ground Element Without Reverse Reach......................................................................... 5-10
Zone 2 Phase-Ground Element With Reverse Reach ............................................................................. 5-13
Zone 3 Phase-Ground Element Without Reverse Reach......................................................................... 5-16
Phase to Phase Units ............................................................................................................................ 5-18
Zone 2 Phase-Phase Element ................................................................................................................ 5-18
Zone 3 Phase-Phase Element ................................................................................................................ 5-20
3-Phase Units ........................................................................................................................................ 5-21
Zone 2 3-Phase Units............................................................................................................................. 5-22
Zone 3 3-Phase Units............................................................................................................................. 5-23
Out of Step System Functional Tests........................................................................................................... 5-24
In-Service Checks ........................................................................................................................................ 5-26
Potential and Current Circuits ....................................................................................................................... 5-26
Current Differential Checks ........................................................................................................................... 5-27
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