Schweitzer Engineering Laboratories SEL-311L, Instruction Manual, Page: 227 / 734

Date Code 20010625 Close and Reclose Logic 6-9
SEL-311L Instruction Manual
See Additional Settings Example 2 that follows in this subsection.
Settings Example
Refer to the top of Figure 6.2.
The example setting for the SEL
OGIC
control equation reclose supervision setting is:
79CLS = 1 (numeral 1)
The example setting for the Reclose Supervision Limit Timer setting is:
79CLSD = 0.00 cycles
Any time a reclosing relay open interval times out, it propagates immediately through Figure 6.2
and then on to Figure 6.1, because SEL
OGIC
control equation setting 79CLS is always asserted to
logical 1. Effectively, there is no special reclose supervision.
Additional Settings Example 1
Refer to the top of Figure 6.2 and Figure 6.4.
SEL-311L Relays are installed at both ends of a transmission line in a high-speed reclose
scheme. After both circuit breakers open for a transmission line fault, the SEL-311L(1) Relay
recloses circuit breaker 52/1 first, followed by the SEL-311L(2) Relay reclosing circuit breaker
52/2, after a synchronism check across circuit breaker 52/2.
Figure 6.4: SEL-311L Relays in a Two-Terminal Application With Reclosing
SEL-311L(1) Relay
Before allowing circuit breaker 52/1 to be reclosed after an open interval time-out, the
SEL-311L(1) Relay verifies that Bus 1 voltage is hot and the transmission line voltage is dead.
This requires reclose supervision settings:
79CLSD = 0.00 cycles (only one check)
79CLS = 3P59 * 27S