ABB RELION REX640 - Page 1253

Multiplexer
The multiplexer connects an input signal to an output based on the value of the
Scheme type setting.
Table 1190: Connected inputs based on the Scheme type value
Scheme type value Inputs connected to an output
"Intertrip"
CR_INTER_TR
"Permissive Underreach" or "Permissive Over-
reach"
CR_PRM
"Blocking"
CR_BLOCKING
Direct underreaching transfer trip scheme DUTT
The direct intertrip scheme is enabled with Scheme type = "Intertrip".
In the direct intertrip scheme, the start signal from the underreaching
(instantaneous) residual overcurrent function DEFHPDEF is connected to the CSUR
input to create a carrier send CS_INTER_TR signal. The duration of the CSUR input
signal can be prolonged by the
Carrier Min Dur setting to ensure a sufficient
duration for the CS_INTER_TR signal.
The local circuit breaker is directly tripped (activation of the OPERATE output) with
the carrier received CS_INTER_TR signal after a settable pick-up delay Coordination
time has elapsed without further local criteria.
The unblocking function (
Unblock mode = "Permanent" and Unblock
mode = "Time window") must not be enabled with the DUTT scheme,
as the lost guard signal results in an immediate trip of the local circuit
breaker.
The activation of the BLOCK input totally blocks the direct intertrip scheme. The
CS_PRM and OPERATE outputs can be blocked by the BLK_CS_OPR input.
~ ~
CB_A
CB_B
TRIP_CB_A
TRIP_CB_B
DEFH_START
3
3
Bus A
Bus B
Figure 711: Simplified functional diagram of the direct intertrip scheme
1MRS759142 F
Protection related functions
REX640
Technical Manual
1253