ABB Relion 670 Series Applications Manual page 215

1MRK 511 401-UUS F
IRecInhibit = 10% (of IBase ); Current level under which function will detect that SCB is disconnected
from the power system
tReconnInhibit = 300s ; Time period under which SCB shall discharge remaining residual voltage to
less than 5%.
Overcurrent feature:
OperationOC = Enabled ; to enable this feature
PU 51 = 135% (of IBase ); Current level for overcurrent pickup. Selected value gives pickup
recommended by international standards.
tOC = 30s ; Time delay for overcurrent trip
Undercurrent feature:
Operation37 = Enabled ; to enable this feature
PU_37 = 70% (of IBase ); Current level for undercurrent pickup
tUC = 5s ; Time delay for undercurrent trip
Reactive power overload feature:
Operation QOL = Enabled ; to enable this feature
UP_QOL = 130% (of SCB MVAr rating); Reactive power level required for pickup. Selected value
gives pickup recommended by international standards.
tQOL = 60s ; Time delay for reactive power overload trip
Harmonic voltage overload feature:
OperationHOL = Enabled ; to enable this feature
Settings for definite time delay step
HOL_DT_V = 200% (of SCB voltage rating); Voltage level required for pickup
tHOL_DT = 10s ; Definite time delay for harmonic overload trip
Settings for IDMT delay step
PU_HOL_DT_V = 110% (of SCB voltage rating); Voltage level required for pickup of IDMT stage.
Selected value gives pickup recommended by international standards.
k_HOL_IDMT = 1.0 ; Time multiplier for IDMT stage. Selected value gives operate time in accordance
with international standards
tMax_HOL_IDMT = 2000s ; Maximum time delay for IDMT stage for very low level of harmonic
overload
Bay control REC670
Application manual
Undercurrent feature is blocked by operation of Reconnection inhibit feature.
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Section 8
Current protection
209