ABB RELION REX640 Technical Manual page 1163

1MRS759142 C
REX640
Technical Manual
Bus A
~
3
CB_A
GUID-9BC0991C-6074-4824-88E7-6A85816DCAA0 V1 EN
Figure 624: Simplified functional diagram of the direct intertrip scheme
Permissive underreaching transfer trip scheme PUTT
The permissive underreach scheme is enabled with Scheme type = "Permissive
Underreach".
In the permissive underreach scheme, the start signal from the underreaching
(instantaneous) residual overcurrent function DEFHPDEF is connected to the CSUR
input to create a CS_PRM signal. The duration of the CSUR input signal can be
prolonged by the Carrier Min Dur setting to ensure a sufficient duration of the
CS_PRM signal.
In the permissive underreach scheme, the CR_PRM signal or CRL signal, if the
unblocking function is enabled, is used to allow the overreaching residual overcurrent
function DEFLPDEF to trip (activation of the OPERATE output) after the pick-up
delay Coordination time. The start signal from the overreaching function is connected
to the CACC input. A general start signal in the forward direction can also be connected
to the CACC input.
The CS_PRM signal is also generated if the CR_PRM signal is received and the local
carrier acceleration signal CACC is active.
Activating the BLOCK input totally blocks the permissive underreach scheme. The
CS_PRM and OPERATE outputs can be blocked by the BLK_CS_OPR input.
Protection related functions
TRIP_CB_A
DEFH_START
Section 5
Bus B
~
3
CB_B
TRIP_CB_B
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