3-18 Overcurrent, Voltage, Synchronism Check, and Frequency Elements Date Code 20010307
SEL-351A Instruction Manual
Accuracy
3LFNXS $VHFRQGDU\DQGRIVHWWLQJ$QRPLQDOSKDVHFXUUHQWLQSXWV,$,%,&
$VHFRQGDU\DQGRIVHWWLQJ$QRPLQDOSKDVHFXUUHQWLQSXWV,$,%,&
&XUYH7LPLQJ F\FOHVDQGRIFXUYHWLPHIRUFXUUHQWVEHWZHHQDQGLQFOXGLQJ
DQGPXOWLSOHVRISLFNXS
Logic Outputs (51PT Element Example)
7KHUHVXOWDQWORJLFRXWSXWVLQ)LJXUHDUHWKHIROORZLQJ5HOD\:RUGELWV
7DEOH3KDVH7LPH2YHUFXUUHQW(OHPHQW0D[LPXP3KDVH/RJLF2XWSXWV
5HOD\:RUG%LW 'HILQLWLRQ,QGLFDWLRQ $SSOLFDWLRQ
3 0D[LPXPSKDVHFXUUHQW,
3
LV
JUHDWHUWKDQSKDVHWLPH
RYHUFXUUHQWHOHPHQWSLFNXS
VHWWLQJ33
(OHPHQWSLFNXSWHVWLQJRURWKHU
FRQWURO
DSSOLFDWLRQV6HH7ULS
/RJLFLQ6HFWLRQ7ULSDQG
7DUJHW/RJLF
37 3KDVHWLPHRYHUFXUUHQWHOHPHQWLV
WLPHGRXWRQLWVFXUYH
7ULSSLQJDQGRWKHUFRQWURO
DSSOLFDWLRQV6HH7ULS/RJLFLQ
6HFWLRQ7ULSDQG7DUJHW/RJLF
35 3KDVHWLPHRYHUFXUUHQWHOHPHQWLV
IXOO\UHVHW
(OHPHQWUHVHWWHVWLQJRURWKHU
FRQWURODSSOLFDWLRQV
Torque Control Switch Operation (51PT Element Example)
Torque Control Switch Closed
7KHSLFNXSFRPSDUDWRULQ)LJXUHFRPSDUHVWKHSLFNXSVHWWLQJ33WRWKHPD[LPXPSKDVH
FXUUHQW,
3
LIWKH7RUTXH&RQWURO6ZLWFKLVFORVHG,
3
LVDOVRURXWHGWRWKHFXUYHWLPLQJUHVHW
WLPLQJIXQFWLRQV7KH5HOD\:RUG%LWVORJLFRXWSXWVRSHUDWHDVIROORZVZLWKWKH7RUTXH&RQWURO
6ZLWFKFORVHG
3 ORJLFDOLI,
3
!SLFNXSVHWWLQJ33DQGWKHSKDVHWLPHRYHUFXUUHQWHOHPHQWLV
WLPLQJRULVWLPHGRXWRQLWVFXUYH
ORJLFDOLI,
3
SLFNXSVHWWLQJ33
37 ORJLFDOLI,
3
!SLFNXSVHWWLQJ33DQGWKHSKDVHWLPHRYHUFXUUHQWHOHPHQWLV
WLPHGRXWRQLWVFXUYH
ORJLFDOLI,
3
!SLFNXSVHWWLQJ33DQGWKHSKDVHWLPHRYHUFXUUHQWHOHPHQWLV
WLPLQJEXWQRW\HWWLPHGRXWRQLWVFXUYH
ORJLFDOLI,
3
SLFNXSVHWWLQJ33