Schweitzer Engineering SEL-351P, Quick Start Manual

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Date Code 990215 Close and Reclose Logic 6-9
SEL-351P Manual Técnico
Settings Example 1
Refer to the top of Figure SECTION 6: .2 and Figure SECTION 6: .4.
SEL-351Ps 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-351P(1) recloses circuit
breaker 52/1 first, followed by the SEL-351P(2) reclosing circuit breaker 52/2, after a
synchronism check across circuit breaker 52/2.
Figure SECTION 6: .4: SEL-351P Recloser Controls Installed at Both Ends of a
Transmission Line in a High-Speed Reclose Scheme
SEL-351P(1) Recloser Control
Before allowing circuit breaker 52/1 to be reclosed after an open interval time-out, the
SEL-351P(1) checks 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
where:
3P59 = all three Bus 1 phase voltages (VA, VB, and VC) are hot
27S = monitored single-phase transmission line voltage (channel VS) is dead
SEL-351P(2) Recloser Control
The SEL-351P(2) checks that Bus 2 voltage is hot, the transmission line voltage is hot, and in
synchronism after the reclosing relay open interval times out, before allowing circuit breaker
52/2 to be reclosed. This requires reclose supervision settings:
79CLSD = 0.00 cycles (only one check)
79CLS = 25A1
where:
25A1 = selected Bus 2 phase voltage (VA, VB, or VC) is in synchronism with
monitored single-phase transmission line voltage (channel VS) and both are
hot