/PERATING INSTRUCTIONS
3*
6
# ' #
#HECKING THE REVERSE INTERLOCK
SCHEME
IF USED
&OR USE AND TESTS OF THE REVERSE INTERLOCK SCHEME IT IS
NECESSARY THAT AT LEAST ONE OF THE BINARY INPUTS HAS
BEEN ASSIGNED TO THE FUNCTION
) BLOCK
AND
OR FURTHER BLOCKING INPUTS 4ESTS CAN BE PERFORMED
WITH PHASE CURRENTS OR EARTH CURRENT 7ITH EARTH CUR
RENT THE CORRESPONDING EARTH CURRENT PARAMETERS ARE
VALID
2EVERSE INTERLOCKING CAN BE USED IN NORMALLY OPEN
MODE IE THE ) STAGES ARE BLOCKED WHEN THE
BINARY INPUT
) BLOCK
IS ENERGIZED OR NOR
MALLY CLOSED MODE IE THE ) STAGES ARE BLOCKED
WHEN THE BINARY INPUT
) BLOCK
IS DE ENER
GIZED 4HE FOLLOWING PROCEDURE IS VALID FOR NORMALLY
OPEN MODE
4HE PROTECTION RELAY ON THE INCOMING FEEDER AND
THOSE ON ALL OUTGOING CIRCUITS MUST BE IN OPERATION
!T FIRST THE AUXILIARY VOLTAGE FOR REVERSE INTERLOCKING
SHOULD NOT BE SWITCHED ON
!PPLY A TEST CURRENT WHICH MAKES PICK UP THE )
STAGE AS WELL AS THE ) OR )
P
STAGE "ECAUSE OF THE
ABSENCE OF THE BLOCKING SIGNAL THE RELAY TRIPS AFTER
THE SHORT DELAY TIME 4 )
#AUTION
4EST CURRENTS LARGER THAN TIMES )
.
MAY
OVERLOAD AND DAMAGE THE RELAY IF APPLIED
CONTINUOUSLY REFER TO 3ECTION FOR
OVERLOAD CAPABILITY /BSERVE A COOLING
DOWN PERIOD
.OW SWITCH ON THE DC VOLTAGE FOR THE REVERSE INTER
LOCKING 4HE TEST AS DESCRIBED ABOVE IS REPEATED
WITH THE SAME RESULT
3IMULATE A PICK UP ON EACH PROTECTIVE DEVICE ON ALL
OUTGOING FEEDERS 3IMULTANEOUSLY A SHORT CIRCUIT IS
SIMULATED ON THE INCOMING FEEDER AS DESCRIBED BE
FORE 4RIPPING NOW OCCURS AFTER THE DELAYED TIME 4
) FOR DEFINITE TIME PROTECTION OR CORRESPONDING TO
4 )P FOR INVERSE TIME PROTECTION
4HESE TESTS HAVE SIMULTANEOUSLY PROVED THAT THE WIR
ING BETWEEN THE PROTECTION RELAYS IS CORRECT
#HECKING THE CIRCUIT BREAKER
FAILURE PROTECTION
4HE PROTECTION FUNCTION ITSELF HAS ALREADY BEEN
TESTED ACCORDING TO 3ECTION
4HE MOST IMPORTANT CONSIDERATION DURING CHECKS
WITH THE POWER PLANT IS THAT THE DISTRIBUTION OF THE TRIP
COMMANDS FOR THE ADJACENT CIRCUIT BREAKERS IS
CHECKED FOR CORRECTNESS
4HE ADJACENT CIRCUIT BREAKERS ARE ALL THOSE WHICH
MUST BE TRIPPED IN CASE OF FAILURE OF THE CONSIDERED
FEEDER BREAKER SO THAT THE SHORT CIRCUIT CURRENT WILL
BE INTERRUPTED 4HESE ARE THE CIRCUIT BREAKERS OF ALL
FEEDERS WHICH FEED THE BUS BAR SECTION TO WHICH
THE CONSIDERED FAULTY FEEDER IS CONNECTED
! GENERAL AND DETAILED DESCRIPTION OF THE CHECKING
PROCEDURE IS NOT POSSIBLE SINCE THE DEFINITION OF THE
ADJACENT CIRCUIT BREAKERS IS WIDELY DEPENDENT OF THE
CONFIGURATION OF THE POWER PLANT
0ARTICULARLY IN CASE OF MULTI SECTION BUS BARS IT IS OF
UTMOST IMPORTANCE THAT THE DISTRIBUTION LOGIC FOR THE
ADJACENT CIRCUIT BREAKERS IS CHECKED &OR THIS IT MUST
BE CHECKED FOR EACH BUS BAR SECTION THAT IN CASE
OF FAILURE OF THE CIRCUIT BREAKER OF THE CONSIDERED
FEEDER ALL THOSE CIRCUITS BREAKERS ARE TRIPPED WHICH
CAN FEED TO THE SAME BUS BAR SECTION BUT THAT NO
OTHER BREAKER IS TRIPPED
)F THE CIRCUIT BREAKER TRIP SIGNAL SHOULD ALSO TRIP THE
CIRCUIT BREAKER OF THE OPPOSITE LINE END OF THE FEEDER
UNDER CONSIDERATION THEN THE TRANSMISSION CHANNEL
FOR THIS REMOTE TRIP MUST BE CHECKED TOO
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