6-30
Close and Reclose Logic
Date Code 20010625
SEL-311L Instruction Manual
Now the SEL-311L Relay cannot operate on its faster-set phase time-overcurrent element T50PT
because the shot counter is at shot = 1 (SH0 = logical 0):
TR
= T50PT * (SHO) + T51PT
= T50PT * (logical 0) + T51PT
=
T51PT
Figure 6.9: Operation of SEL-311L Relay Shot Counter for Sequence Coordination With
Line Recloser (Additional Settings Example 2)
The line recloser continues to operate for the permanent fault beyond it, but the SEL-311L Relay
shot counter does not continue to increment. Sequence coordination setting 79SEQ is effectively
disabled by the shot counter incrementing from shot = 0 to shot = 1.
79SEQ
= 79RS * T50P * SH0 = 79RS * T50P * (logical 0) = logical 0
The shot counter stays at shot = 1.
Thus, if there is a coincident fault between the SEL-311L Relay and the line recloser, the
SEL-311L Relay will operate on T51PT and then reclose once, instead of going straight to the
Lockout State (shot = 1 < last shot = 2).
As stated earlier, the reset time setting 79RSD takes the shot counter back to shot = 0 after a
sequence coordination operation increments the shot counter. Make sure that reset time setting
79RSD is set long enough to maintain the shot counter at shot = 1 as shown in Figure 6.9.
Summary of Contents for SEL-311L
Page 6: ......
Page 8: ......
Page 26: ......
Page 54: ......
Page 144: ......
Page 216: ......
Page 252: ......
Page 302: ......
Page 338: ......
Page 480: ......
Page 484: ......
Page 486: ......
Page 502: ......
Page 532: ...12 28 Standard Event Reports and SER Date Code 20010625 SEL 311L Instruction Manual 4 ...
Page 552: ......
Page 554: ......
Page 574: ......
Page 576: ......
Page 596: ......
Page 602: ......
Page 628: ......
Page 656: ......
Page 662: ......
Page 664: ......
Page 688: ......
Page 700: ......
Page 716: ......
Page 722: ......
Page 734: ......