ABB RELION REX640 Technical Manual page 1148

Section 5
Protection related functions
1142
Bus A
~
3
CB_A
GUID-8F4D3B6C-1C7D-4E6F-B2AD-40B96D6B46E4 V1 EN
Figure 617: 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 zone Z1
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 the CRL signal if the
unblocking function is enabled, is used to allow the overreaching zone Z2 to trip
(activation of the OPERATE output) after the pick-up delay Coordination Time. The
start signal from the overreaching zone Z2 is connected to the CACC input.
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.
Z1
Z1
TRIP_CB_A
Z1_START
1MRS759142 C
Bus B
~
3
CB_B
TRIP_CB_B
REX640
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