ABB RELION REX640 - Page 646

The timer is activated according to the calculated differential, stabilizing current
and the set differential characteristic.
t
Timer
t
I
Charact.
I
bias
STR_LS_LOC
OPR_LS_LOC
Minimum operate
time
Time multiplier
Operating curve type
Reset delay time
Operate delay time
Low operate value
I_DIFF
(from Differential calculation)
I_BIAS
(from Differential calculation)
BLOCK_LS
ENABLE OPERATION
Slope section 3
Slope section 2
End section 1
End section 2
PROT_ACTIVE
(from Fail safe function)
BLKD2H_LOC
(from Inrush detector)
BLKD2H_REM
(from Inrush detector)
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:
Protection functions
1MRS759142 F
646 REX640
Technical Manual