Id/Ir
Ib/Ir
Slope
section 2
Low operate value
OPERATE
AREA (LS)
NON-OPERATE
AREA (LS & HS)
End section 1
High operate value
OPERATE
AREA (HS)
Slope
section 3
End section 2
NON-OPERATE
AREA (LS)
Figure 413: Operating characteristics of the protection. LS stands for the biased low
stage and HS for the instantaneous high stage
The OPERATE output is always activated with the OPR_HS output. The internal
blocking signals of the differential function do not prevent the trip signal of the
instantaneous differential current stage from being activated. When required, the
operating outputs of Instantaneous high stage can be blocked by the external
control signals BLK_OPR_HS or BLOCK.
OPERATE
I_D
(from Differential calculation)
High operate value
OPR_HS
BLOCK
BLK_OPR_HS
Fault in protected area
(from Differential calculation)
Figure 414: Operation logic of Instantaneous high stage
External blocking functionality
TR3PTDF has three inputs for blocking.
1MRS759142 F
Protection functions
REX640
Technical Manual
729