Table 1182: 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 zone Z1 is
connected to the CSUR input to create a carrier send CS_INTER_TR signal. The
duration of the CSUR input signal is 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.
~ ~
Z1
Z1
CB_A CB_B
TRIP_CB_A
TRIP_CB_B
Z1_START
Bus A
Bus B
3
3
Figure 704: 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".
1MRS759142 F Protection related functions
REX640
Technical Manual
1239
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