3-6 Overcurrent, Voltage, Synchronism Check, Frequency, and Power Elements Date Code 20010112
SEL-351S Instruction Manual
,QSXW,1DVVHUWHG37& ,1 ORJLFDO
7KHQRQO\WKHFRUUHVSRQGLQJGLUHFWLRQDOFRQWUROLQSXWIURP)LJXUHKDV
WREHFRQVLGHUHGLQWKHFRQWURORISKDVHLQVWDQWDQHRXVGHILQLWHWLPHRYHU
FXUUHQWHOHPHQWV337
,IGLUHFWLRQDOFRQWUROHQDEOHVHWWLQJ( 1WKHQSKDVHLQVWDQWDQHRXV
GHILQLWHWLPHRYHUFXUUHQWHOHPHQWV337DUHHQDEOHGDQG
QRQGLUHFWLRQDO
6RPHWLPHV6(/
2*,&FRQWUROHTXDWLRQWRUTXHFRQWUROVHWWLQJVDUHVHWWRSURYLGHGLUHFWLRQDO
FRQWURO6HH'LUHFWLRQDO&RQWURO3URYLGHGE\7RUTXH&RQWURO6HWWLQJVDWWKHHQGRI6HFWLRQ
/RVVRI3RWHQWLDO/RDG(QFURDFKPHQWDQG'LUHFWLRQDO(OHPHQW/RJLF
Combined Single-Phase Instantaneous Overcurrent Elements
7KHVLQJOHSKDVHLQVWDQWDQHRXVRYHUFXUUHQWHOHPHQW5HOD\:RUGELWRXWSXWVLQ)LJXUHDUH
FRPELQHGWRJHWKHULQ)LJXUHRQDSHUSKDVHEDVLVSURGXFLQJ5HOD\:RUGELWRXWSXWV$
%DQG&
5HOD\:RUGELWV$%DQG&FDQEHXVHGWRLQGLFDWHWKHSUHVHQFHRUDEVHQFHRIFXUUHQWLQ
DSDUWLFXODUSKDVH
)LJXUH&RPELQHG6LQJOH3KDVH,QVWDQWDQHRXV2YHUFXUUHQW(OHPHQWV
Pickup and Reset Time Curves
)LJXUHDQG)LJXUHVKRZSLFNXSDQGUHVHWWLPHFXUYHVDSSOLFDEOHWRDOOQRQGLUHFWLRQDO
LQVWDQWDQHRXVRYHUFXUUHQWHOHPHQWVLQWKH6(/65HOD\+]RU+]UHOD\V7KHVHWLPHV
GRQRW
LQFOXGHRXWSXWFRQWDFWRSHUDWLQJWLPHDQGWKXVDUHDFFXUDWHIRUGHWHUPLQLQJHOHPHQW
RSHUDWLRQWLPHIRUXVHLQLQWHUQDO6(/
2*,&FRQWUROHTXDWLRQV2XWSXWFRQWDFWSLFNXSGURSRXW
WLPHLVPVF\FOHIRUD+]UHOD\F\FOHIRUD+]UHOD\