Schweitzer Engineering Laboratories SEL-351 - Factory Settings Example

6-10 Close and Reclose Logic Date Code 20001006
SEL-351 Instruction Manual
The unlatching of the sealed-in reclosing relay open interval time-out condition by the assertion of
SELOGIC Control Equation setting 79CLS indicates successful propagation of a reclosing relay
open interval time-out condition on to the close logic in Figure 6.1.
See Additional Settings Example 2 that follows in this subsection.
Factory Settings Example
Refer to the top of Figure 6.2.
The factory setting for the SELOGIC Control Equation reclose supervision setting is:
79CLS = 1 (numeral 1)
The factory 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 SELOGIC 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-351 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-351(1) Relay recloses circuit
breaker 52/1 first, followed by the SEL-351(2) Relay reclosing circuit breaker 52/2, after a
synchronism check across circuit breaker 52/2.
Figure 6.4: SEL-351 Relays Installed at Both Ends of a Transmission Line in a High-Speed
Reclose Scheme
Courtesy of NationalSwitchgear.com