-ETHOD OF OPERATION
6+
6
# ' #
!UTOMATIC RECLOSURE
'ENERAL
%XPERIENCE HAS SHOWN THAT APPROXIMATELY OF
SHORT CIRCUITS ARE CAUSED BY AN ARC ON OVERHEAD
LINES AND SELF EXTINGUISH AFTER INTERRUPTION BY THE
PROTECTIVE DEVICE 4HE LINE CAN THEREFORE BE RE EN
ERGIZED 4HIS IS CARRIED OUT BY THE AUTOMATIC RECLO
SURE !2 FUNCTION &IGURE SHOWS AN EXAMPLE FOR
THE TIME SEQUENCE OF A TWO SHOT AUTO RECLOSURE
WITH A 2!2 CYCLE FOLLOWED BY A $!2 CYCLE
)F THE CIRCUIT BREAKER POLES CAN BE TRIPPED INDIVIDUAL
LY THEN !2 IS OFTEN CARRIED OUT SINGLE POLE FOR SING
LE PHASE FAULTS AND THREE POLE FOR MULTI PHASE
FAULTS IN NETWORKS WITH EARTHED STARPOINT )F THE SHORT
CIRCUIT IS STILL PRESENT AFTER THE AUTO RECLOSURE ARC
NOT QUENCHED OR METALLIC SHORT CIRCUIT THEN THE PRO
TECTIVE RELAY FINALLY DISCONNECTS THE POWER -ULTIPLE
AUTO RECLOSURE ATTEMPTS OFTEN WITH A FIRST RAPID
AUTO RECLOSURE 2!2 AND SUBSEQUENT DELAYED
AUTO RECLOSE CYCLES $!2 ARE POSSIBLE IN SOME
NETWORKS
6+ ALLOWS AUTOMATIC THREE POLE SINGLE POLE
SINGLE AND THREE POLE AS WELL AS SINGLE AND MUL
TI SHOT RECLOSURE 7ITH MULTI SHOT AUTO RECLOSURE
THE FIRST SHOT IS DESIGNATED WITH 2!2 RAPID AUTO RE
CLOSURE AND THE SUBSEQUENT SHOTS ARE DESIGNATED
WITH $!2 DELAYED AUTO RECLOSURE INDEPENDENT ON
THE REAL SETTING OF THE DEAD TIMES OF THE AUTO RE
CLOSE CYCLES
)N ORDER TO PERFORM SINGLE POLE OR SINGLE
AND
THREE POLE AUTO RECLOSURE IT IS NECESSARY THAT THE
FEEDER PROTECTION IS ABLE TO ISSUE PHASE SEGREGATED
TRIP COMMANDS
3IGNAL EXCHANGE BETWEEN THE FEEDER PROTECTION AND
THE 6+ AUTO RECLOSE UNIT MUST BE ACCOM
PLISHED VIA THE BINARY INPUTS AND OUTPUTS OF THE UNIT
&URTHERMORE IT IS ALSO POSSIBLE TO ALLOW THE 6+
TO BE TRIGGERED FROM MORE THAN ONE PROTECTION RELAYS
EG MAIN PROTECTION AND ALTERNATE PROTECTION SEE
3ECTION )N THIS CASE 6+ CAN PERFORM
THREE POLE COUPLING FOR BOTH FEEDER PROTECTION RE
LAYS IF ONLY ONE RELAY TRIPS MULTI POLE OR IF THE PROTEC
TION RELAYS MAKE ATTEMPT TO TRIP SINGLE POLE IN DIFFER
ENT PHASES
4HE USE OF TWO 6+ RELAYS WITH TWO FEEDER PRO
TECTION RELAYS IS ALSO POSSIBLE AS WELL AS THE USE OF
ONE 6+ WITH A FEEDER PROTECTION AND A SECOND
AUTO RECLOSE RELAY WITH SEPARATE FEEDER PROTECTION
EXAMPLE SEE 3ECTION
4HE POSSIBLE PROGRAMS OF THE !2 FUNCTION FOR THE
FIRST !2 CYCLE DESIGNATED IN THE FOLLOWING WITH 2!2
RAPID AUTO RECLOSURE ARE
2!2 02/'
4(2%% 0/,%
IE ALL TYPES OF
FAULTS RESULT IN THREE POLE !2
2!2 02/'
3).',% 0/,%
IE SINGLE
PHASE FAULTS RESULT IN SINGLE
POLE !2 MULTI PHASE FAULTS IN
THREE POLE FINAL DISCONNECTION
2!2 02/'
3).',%4(2%% 0/,
E
IE
SINGLE PHASE FAULTS RESULT IN
SINGLE POLE !2 MULTI PHASE
FAULTS IN THREE POLE !2
)F MORE THAN ONE RECLOSE ATTEMPT WILL BE CARRIED OUT
THE SECOND AND ANY FURTHER AUTO RECLOSE CYCLE ARE
DESIGNATED IN THE FOLLOWING WITH $!2 DELAYED
AUTO RECLOSURE INDEPENDENT ON THE SETTING OF THE
DEAD TIMES OF THE CYCLES )T IS POSSIBLE TO SKIP THE
2!2 CYCLE SO THAT ONLY $!2 CYCLES OCCUR $!2
CYCLES ARE ALWAYS THREE POLE &OR THE $!2 FUNC
TION THE FOLLOWING PROGRAMS ARE SELECTABLE
$!2 02/'
./ $!2
IE NO $!2 OCCURS UN
SUCCESSFUL 2!2 RESULTS IN FINAL
TRIP
$!2 02/'
$!2 7)4(/54 2!2
IE $!2
CYCLES CAN BE CARRIED OUT EVEN
WITHOUT A PRECEDING 2!2 CYCLE
EG 2!2 IS BY PASSED BE
CAUSE BLOCKED
$!2 02/'
$!2 !&4%2 2!2
IE THE $!2
CYCLES CAN ONLY BE INITIATED AFTER
AN UNSUCCESSFUL 2!2
0REREQUISITE FOR INITIATION OF THE !2 FUNCTION IS AL
WAYS THAT THE CIRCUIT BREAKER IS READY FOR OPERATION
WHEN PICK UP OCCURS 4HIS INFORMATION IS TRANS
MITTED TO THE DEVICE VIA A BINARY INPUT
&URTHERMORE RECLOSURE IS BLOCKED IF THE TRIPPING
COMMAND OCCURS AFTER THE ACTION TIME WHICH CAN BE
SET INDIVIDUALLY FOR 2!2 AND $!2
