ABB Relion 670 series - Intertrip scheme; Simplified logic diagram

CR_GUARD
0-tSecurity
0
150 ms
CR
CRL
LCG
AND
OR
AND
en05000746_ansi.vsd
0
0
200 ms
NOT
OR
ANSI05000746 V1 EN
Figure 388: Guard signal logic with unblocking schemeGuard singal logic with
unblocking scheme and with setting Unblock = Restart
The unblocking function can be set in three operation modes (setting Unblock):
Disabled The unblocking function is out of operation
No restart Communication failure shorter than tSecurity will be ignored
If CR_GUARD disappears a CRL signal will be transferred to the trip logic
There will not be any information in case of communication failure (LCG)
Restart Communication failure shorter than tSecurity will be ignored
It sends a defined (150 ms) CRL after the disappearance of the CR_GUARD signal
The function will activate LCG output in case of communication failure
If the communication failure comes and goes (<200 ms) there will not be recurrent
signalling
13.1.2.5 Intertrip scheme
In the direct intertrip scheme, the send signal CS is sent from an underreaching zone
that is tripping the line.
The received signal CR is directly transferred to a TRIP for tripping without local
criteria. The signal is further processed in the tripping logic.
In case of single-pole tripping in multi-phase systems, a phase selection is performed.
13.1.2.6 Simplified logic diagram
The simplified logic diagram for the complete logic is shown in figure 389.
Section 13 1MRK505222-UUS C
Scheme communication
792
Technical reference manual