-ETHOD OF OPERATION
6+
6
# ' #
)NTERROGATION FOR READINESS OF
THE CIRCUIT BREAKER
0RE CONDITION FOR A RECLOSE ATTEMPT AFTER SHORT CIR
CUIT INTERRUPTION IS THAT THE CIRCUIT BREAKER IS READY FOR
AT LEAST ONE 42)0 #,/3% 42)0 CYCLE WHEN THE
!2 FUNCTION IS INITIATED IE AT THE INSTANT OF TRIP COM
MAND 4HE READINESS INFORMATION FROM THE BREAKER
HAS TO BE TRANSMITTED TO THE DEVICE VIA A BINARY INPUT
)N CASE THAT SUCH READINESS INFORMATION IS NOT AVAIL
ABLE INTERROGATION CAN BE SUPPRESSED SINCE OTHER
WISE NO AUTO RECLOSE WOULD BE POSSIBLE AT ALL
7HEN SINGLE SHOT AUTO RECLOSURE IS PERFORMED IT IS
SUFFICIENT TO INTERROGATE THE BREAKER READINESS ONE
SINGLE TIME BEFORE INITIATION OF !2 !S FOR EXAMPLE
THE AIR PRESSURE FOR BREAKER OPERATION WILL COLLAPSE
DURING THE TRIP EXECUTION NO FURTHER INTERROGATION
SHOULD BE CARRIED OUT
7HEN MULTI SHOT AUTO RECLOSURE IS USED IT IS AD
VANTAGEOUS TO INTERROGATE BREAKER READINESS NOT
ONLY AT THE INSTANT OF THE FIRST TRIP COMMAND BUT ALSO
BEFORE EVERY RECLOSE ATTEMPT OR BEFORE EVERY OTHER
RECLOSE ATTEMPT )F THIS FACILITY IS SELECTED RECLOSURE
IS BLOCKED AS LONG AS THE CIRCUIT BREAKER IS NOT READY
FOR ANOTHER 42)0 #,/3% SEQUENCE
4HE RECOVERY TIME OF THE CIRCUIT BREAKER CAN BE SU
PERVISED BY THE 6+ RELAY 4HIS SUPERVISION TIME
4 #" 3506 WILL RUN AS LONG AS THE CIRCUIT BREAKER
DOES NOT INFORM ABOUT READINESS )N THIS CASE THE
DEAD TIME MAY BE EXTENDED WHEN THE BREAKER IS NOT
READY AFTER EXPIRY OF THE SET DEAD TIME "UT IF THE
BREAKER IS NOT YET READY AFTER EXPIRY OF THE SUPERVI
SION TIME THEN RECLOSURE IS BLOCKED 4HIS BLOCKING IS
CANCELED ONLY AFTER THE LOCK OUT TIME 4",/#+ $9.
REFER 3ECTION HAS ELAPSED )F 4",/#+ $9. IS
SET TO
0
CLOSING IS LOCKED OUT UNTIL THE !2 FUNCTION IS
RESET BY ENERGIZATION OF THE BINARY INPUT
!2 2E
SET
!FTER THE RESET SIGNAL ALL FUNCTIONS RESET TO THE
QUIESCENT CONDITION
4HREE POLE AUTO RECLOSURE
4HE 2!2 FUNCTION OF 6+ INFORMS THE FEEDER PRO
TECTION ABOUT READINESS FOR RECLOSURE BY ITS OUTPUT
SIGNAL
2!2 :ONE 2EL
IN ORDER TO ALLOW THE FEED
ER PROTECTION TO TRIP IN ITS 2!2 ZONE IF AVAILABLE 4HE
ACTION TIME REFER TO 3ECTION OF THE 2!2 FUNC
TION IS STARTED WITH THE FAULT DETECTION SIGNAL OF THE
FEEDER PROTECTION VIA THE BINARY INPUT
3TART !2
4HE FEEDER PROTECTION TRIPS THREE POLE FOR ALL FAULTS
WITHIN THE STAGE VALID FOR 2!2 EG THE DISTANCE PRO
TECTION IN OVERREACHING ZONE 4HE !2 FUNCTION OF
6+ IS INFORMED VIA ANY OF THE BINARY INPUTS
4RIP , !2
2!2 FUNCTION IS INITIATED PROVIDED
TRIPPING OCCURS WITHIN THE ACTION TIME REFER TO 3EC
TION 7ITH FAULT CLEARANCE THE SETTABLE DEAD
TIME 2!2 4 0/, COMMENCES FOR THREE POLE
2!2 SIMULTANEOUSLY THE SIGNAL
2!2 :ONE 2EL
DISAPPEARS /N EXPIRY OF THE DEAD TIME THE CIRCUIT
BREAKER RECEIVES A CLOSING COMMAND THE DURATION
OF WHICH IS SETTABLE AND THE SETTABLE 4HE RECLAIM
TIME 4 2%#,!)- 3ECTION IS STARTED
)F THE FAULT IS CLEARED SUCCESSFUL 2!2 THE RECLAIM
TIME 4 2%#,!)- 3ECTION EXPIRES AND ALL
FUNCTIONS OF 6+ RESET TO THE QUIESCENT CONDI
TION 4HE NETWORK FAULT IS CLEARED THE !2 FUNCTIONS
ARE READY FOR A NEW FAULT
)F THE FAULT HAS NOT BEEN CLEARED UNSUCCESSFUL !2
THEN THE SHORT CIRCUIT PROTECTION CARRIES OUT A FINAL
DISCONNECTION IN THE STAGE THAT IS VALID WITHOUT 2!2
!LSO EVERY FAULT DURING THE RECLAIM TIME WILL RESULT IN
FINAL DISCONNECTION
!FTER UNSUCCESSFUL !2 FINAL DISCONNECTION THE
LOCK OUT TIME 4",/#+ $9. 3ECTION IS
STARTED &OR THIS TIME ANY CLOSE COMMAND FROM
6+ IS LOCKED
4HE ABOVE SEQUENCE COMES INTO EFFECT WITH SINGLE
SHOT 2!2 7ITH 6+ MULTIPLE !2 ATTEMPTS UP
TO $!2 SHOTS REFER TO 3ECTION ARE ALSO POS
SIBLE !DDITIONALLY IT IS POSSIBLE TO SKIP THE 2!2 CYCLE
BY A SIGNAL VIA A BINARY INPUT OF THE DEVICE )N THIS
CASE ONLY $!2 IS EFFECTIVE REFER TO 3ECTION
