Schweitzer Engineering SEL-351P - Settings Example 1; Settings Example 2

7-30 Inputs, Outputs, Timers, and Other Control Logic Date Code 990215
SEL-351P Manual Técnico
Figure SECTION 7: .24: SEL OGIC Control Equation Variables/Timers SV7/SV7T
Through SV16/SV16T
Settings Example 1
A SEL
OGIC Control Equation timer can be used for a simple breaker failure scheme:
SV1 = TRIP
The TRIP Relay Word bit is run through a timer for breaker failure timing. Timer pickup setting
SV1PU is set to the breaker failure time (SV1PU = 12 cycles). Timer dropout setting SV1DO is
set for a 2-cycle dropout (SV1DO = 2 cycles). The output of the timer (Relay Word bit SV1T)
operates output contact OUT103.
OUT103 = SV1T
Settings Example 2
Another application idea is dedicated breaker failure protection (see
Figure SECTION 7: .25):
SV6 = IN101 (breaker failure initiate)
SV7 = (SV7 + IN101) * (50P1 + 50N1)
OUT101 = SV6T (retrip)
OUT102 = SV7T (breaker failure trip)
Figure SECTION 7: .25: Dedicated Breaker Failure Scheme Created with SEL
OGIC
Control Equation Variables/Timers
Note that the above SEL
OGIC Control Equation setting SV7 creates a seal-in logic circuit (as
shown in
Figure SECTION 7: .25) by virtue of SEL OGIC Control Equation setting SV7 being set
equal to Relay Word bit SV7 (SEL
OGIC Control Equation variable SV7):
SV7 = (SV7 + IN101) * (50P1 + 50N1)