Sel SEL-421 - A.8 Relay Word Bits: Synchronism-Check Elements

R.A.28
SEL-421 Relay Reference Manual Date Code 20111215
Relay Word Bits
Row List
27 67Q3T Level 3 negative-sequence delayed directional overcurrent
element
27 67Q4T Level 4 negative-sequence delayed directional overcurrent
element
27 * Reserved
27 * Reserved
27 * Reserved
27 * Reserved
28 51S1 Inverse-Time Overcurrent Element 1 pickup
28 51S1T Inverse-Time Overcurrent Element 1 timed out
28 51S1R Inverse-Time Overcurrent Element 1 reset
28 * Reserved
28 51S2 Inverse-Time Overcurrent Element 2 pickup
28 51S2T Inverse-Time Overcurrent Element 2 timed out
28 51S2R Inverse-Time Overcurrent Element 2 reset
28 * Reserved
29 51S3 Inverse-Time Overcurrent Element 3 pickup
29 51S3T Inverse-Time Overcurrent Element 3 timed out
29 51S3R Inverse-Time Overcurrent Element 3 reset
29 * Reserved
29 * Reserved
29 * Reserved
29 * Reserved
29 * Reserved
Table A.8 Relay Word Bits: Synchronism-Check Elements (Sheet 1 of 2)
Row Name Description
30 59VP VP within “healthy voltage” window
30 59VS1 VS1 within “healthy voltage” window
30 25ENBK1 Circuit Breaker 1 synchronism-check element enable
30 SFZBK1 Circuit Breaker 1 slip frequency less than 5 mHz
30 SFBK1 5 mHz  Circuit Breaker 1 slip frequency < 25 SFBK1
30 25W1BK1 Circuit Breaker 1 Angle 1 within Window 1
30 25W2BK1 Circuit Breaker 1 Angle 2 within Window 2
30 25A1BK1 Circuit Breaker 1 voltages within Synchronism Angle 1
31 25A2BK1 Circuit Breaker 1 voltages within Synchronism Angle 2
31 FAST1 fs1 > fp
31 SLOW1 fs1 < fp
31 BSYNBK1 Block synchronism check for Circuit Breaker 1
31 * Reserved
31 * Reserved
31 * Reserved
Table A.7 Relay Word Bits: Overcurrent Elements (Sheet 2 of 2)
Row Name Description