ABB RELION REX640 Technical Manual page 1162

Section 5
Protection related functions
1156
Multiplexer
The multiplexer connects an input signal to an output based on the value of the Scheme
type setting.
Table 1083: Connected inputs based on the Scheme type value
Scheme type value
"Intertrip"
"Permissive Underreach" or "Permissive
Overreach"
"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 CR_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.
Inputs connected to an output
CR_INTER_TR
CR_PRM
CR_BLOCKING
1MRS759142 C
REX640
Technical Manual