ABB RELION REX640 Technical Manual page 646

Protection functions
The timer is activated according to the calculated differential, stabilizing current
and the set differential characteristic.
PROT_ACTIVE
(from Fail safe function)
BLOCK_LS
I_DIFF
(from Differential calculation)
I_BIAS
(from Differential calculation)
BLKD2H_LOC
(from Inrush detector)
BLKD2H_REM
(from Inrush detector)
End section 1
Slope section 2
End section 2
Slope section 3
Low operate value
Figure 362: Operation logic of the stabilized low stage
The stabilization affects the operation of the function.
Figure 363: Operating characteristics of the protection. (LS) stands for the low
stage and (HS) for the high stage.
The slope of the operating characteristic curve of the differential function varies in
the different sections of the range:
646
ENABLE OPERATION
Charact.
I
I
bias
Timer
t
t
Operating curve type
Operate delay time
Reset delay time
Minimum operate
time
Time multiplier
1MRS759142 F
OPR_LS_LOC
STR_LS_LOC
REX640
Technical Manual