/PERATING INSTRUCTIONS
3$
6
# ' #
#HECKING OF THE CURRENT TRANSFORMER CONNECTIONS AT ONE LINE END
4HE CURRENT TRANSFORMER CONNECTIONS ARE CHECKED
WITH PRIMARY LINE CURRENT 4HIS REQUIRES A LOAD CURRENT
OF AT LEAST OF THE RATED LINE CURRENT THROUGH THE
LINE %NSURE THAT THE POLARITY SWITCH IN THE FRONT IS SI
TUATED IN ONE OF ITS END POSITIONS
4HESE CHECKS SUPPORT THE VISUAL CHECKS OF THE
CORRECT CT CONNECTIONS BUT DO NOT REPLACE THEM
SINCE THE RESULTS OF THESE TESTS DO NOT IDENTIFY THE UN
EQUIVOCAL CAUSES OF ERRORS ! CYCLIC OR ACYCLIC
CHANGE OF THE PHASES FOR EXAMPLE CANNOT BE REC
OGNIZED ! PRECONDITION IS THEREFORE THE COMPLE
TION OF THE CHECKS ACCORDING TO 3ECTION
3ECONDARY INJECTION TEST SET WHICH HAVE BEEN USED
FOR THE FOREGOING CHECKS MUST BE REMOVED 4HE
RELAY MUST BE CONNECTED TO THE CURRENT TRANSFORM
ERS
"EFORE THE LINE IS ENERGIZED IT MUST BE ENSURED THAT
A SHORTCIRCUIT PROTECTION IS EFFECTIVE AT EACH LINE END
)F A SEPARATE BACKUP PROTECTION IS INSTALLED EG AN
OVERCURRENT TIME PROTECTION THIS MUST BE COMMIS
SIONED AND SWITCHED EFFECTIVE
)F NO SEPARATE BACKUP PROTECTION IS AVAILABLE THEN
THE INTEGRATED OVERCURRENT TIME PROTECTION PROVIDED
IN 3$ IS SWITCHED
/.
ADDRESS 4HE TRIP
COMMAND OF THE OVERCURRENT TIME PROTECTION MUST
BE ALLOCATED TO THE TRIP RELAY WHICH TRIPS THE LINE CIR
CUIT BREAKER
)T MUST BE EXPECTED THAT THE INTERNAL
OVERCURRENT TIME PROTECTION TRIPS WHEN A WRONG
CURRENT TRANSFORMER CONNECTION SIMULATES AN IN
CREASED MIXED CURRENT WHICH EXCEEDS THE OVER
CURRENT THRESHOLD 4HIS IS ALSO APPLICABLE FOR THE
OPPOSITE LINE END
4HE DIFFERENTIAL PROTECTION REMAINS BLOCKED AD
DRESS $)&& 02/4
",/#+ 42)0 2%,
C
3WITCH OFF THE EARTHING ISOLATORS AT BOTH LINE ENDS
CLOSE THE CIRCUIT BREAKERS AT BOTH LINE ENDS %N
SURE THAT AT LEAST OF THE RATED LINE CURRENT
FLOWS THROUGH THE LINE IF NECESSARY ACHIEVE THIS
BY SWITCHING OPERATIONS IN THE NETWORK 4HE DIREC
TION OF THE LOAD CURRENT IS IRRELEVANT
C
4HE SUMMATION TRANSFORMER CURRENT CAN BE READ
OFF ON THE DISPLAY IN THE FRONT OR VIA THE OPERATING
INTERFACE IN ADDRESS )F THE CONNECTIONS ARE
CORRECT THIS VALUE CORRESPONDS TO THE ACTUALLY
FLOWING LINE CURRENT REFERRED TO THE RATED RELAY
CURRENT !DDRESS SHOWS THE PRIMARY CURRENT
IN !
- % ! 3
)
4 % 3 4
!FTER CONFIRMATION WITH THE 9ES KEY
*9
THE CURRENT WILL
BE WILL BE MEASURED
#ONFIRM WITH THE 9ES KEY
*9
4HE RELAY MEASURES
THE MIXED OUTPUT CURRENT OF THE SUMMATION CT AND
CALCULATES THE SECONDARY CURRENT REFERRED TO THE
RATED RELAY CURRENT 4HE RESULT IS DISPLAYED IMMEDI
ATELY "UT IF A SYSTEM FAULT IS DETECTED NO MEASURE
MENT CAN TAKE PLACE ! CORRESPONDING MESSAGE IS
DISPLAYED
- % ! 3
)
)
) ) N
4HE CURRENT IS DISPLAYED REFERRED TO RATED RELAY CURRENT
WITH A RESOLUTION OF
|
)
.
EG
|
)
.
& , 4
) .
0 2 / ' 2 % 3 3
! SYSTEM FAULT IS IN PROGRESS
! " / 2 4 % $
MEASUREMENT IS ABORTED
Содержание 7SD502
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