ABB REL 356

ABB REL 356 Current Differential Protection
5-9
Testing
IA
IAR
IB
IBR
IC
ICR
TB6-6
TB6-5
TB6-8
TB6-7
TB6-10
TB6-9
3
∅
Current Test Set
TB6-6
TB6-5
TB6-8
TB6-7
TB6-10
TB6-9
IA
IAR
IB
IBR
IC
ICR
IA
IB
IC IR
External Fault(s) - Current connections
Unit #1 REL356 Unit #2 REL356
STEP 2
Apply fault currents greater than those shown in Tables 5-1, 5-2 & 5-3 and verify that the relay does not trip on external
faults.
Dual Unit Back to Back Test - Internal Faults
To simulate an internal fault, reverse the CT polarity on unit number 2. Test the relay per Tables 5-1, 5-2 & 5-3 by
applying faults and verifying that the relay trips.
Internal Fault(s) - Current connections
IA
IAR
IB
IBR
IC
ICR
TB6-6
TB6-5
TB6-8
TB6-7
TB6-10
TB6-9
3
Æ
Current Test Set
TB6-6
TB6-5
TB6-8
TB6-7
TB6-10
TB6-9
IA
IAR
IB
IBR
IC
ICR
IA
IB
IC IR