ABB RED650, Applications Manual

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tCoord : Delay time for trip from ECPSCH function. For Permissive under/
overreaching schemes, this timer shall be set to at least 20 ms plus maximum reset
time of the communication channel as a security margin. For Blocking scheme, the
setting should be > maximum signal transmission time +10 ms.
Unblock : Select Off if unblocking scheme with no alarm for loss of guard is used.
Set to Restart if unblocking scheme with alarm for loss of guard is used.
tSendMin : Time duration, the carrier send signal is prolonged.
tSecurity : The absence of CRG signal for a time duration of tSecurity is considered
as CR signal.
13.5 Current reversal and weak-end infeed logic for
residual overcurrent protection ECRWPSCH
IP14365-1 v4
13.5.1 Identification
M14883-1 v2
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Current reversal and weak-end infeed
logic for residual overcurrent protection
ECRWPSCH - 85
13.5.2 Application
IP15041-1 v1
13.5.2.1 Fault current reversal logic
M15285-3 v7
Figure 124 and figure 125 show a typical system condition, which can result in a
fault current reversal.
Assume that fault is near the B1 breaker. B1 Relay sees the fault in Zone1 and A1
relay identifies the fault in Zone2.
Note that the fault current is reversed in line L2 after the breaker B1 opening.
It can cause an unselective trip on line L2 if the current reversal logic does not
block the permissive overreaching scheme in the IED at B2.
1MRK 505 393-UEN B
Section 13
Scheme communication
Line differential protection RED650 2.2 IEC 291
Application manual