ABB REC670 Applications Manual page 226

Section 8
Current protection
220
General Settings:
Operation =On; to enable the function
IBase =289A; Fundamental frequency SCB rated current in primary amperes. This
value is used as a base value for pickup settings of all other features integrated in
this function.
Reconnection inhibit feature:
OperationRecIn =On; to enable this feature
IRecnInhibit< =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 =On; to enable this feature
IOC> =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:
OperationUC =On; to enable this feature
IUC< =70% (of IBase); Current level for undercurrent pickup
tUC =5s; Time delay for undercurrent trip
Undercurrent feature is blocked by operation of Reconnection
inhibit feature.
Reactive power overload feature:
OperationQOL =On; to enable this feature
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 =On; to enable this feature
Settings for definite time delay step
1MRK 511 401-UEN A
Bay control REC670 2.2 IEC
Application manual