Schweitzer Engineering SEL-351P, Быстрый старт

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Date Code 990215 Inputs, Outputs, Timers, and Other Control Logic 7-31
SEL-351P Manual Técnico
Optoisolated input IN101 functions as a breaker failure initiate input. Phase instantaneous
overcurrent element 50P1 and neutral ground instantaneous overcurrent element 50N1 function
as fault detectors.
Timer pickup setting SV6PU provides retrip delay, if desired (can be set to zero). Timer dropout
setting SV6DO holds the retrip output (output contact OUT101) closed for extra time if needed
after the breaker failure initiate signal (IN101) goes away.
Timer pickup setting SV7PU provides breaker failure timing. Timer dropout setting SV7DO
holds the breaker failure trip output (output contact OUT102) closed for extra time if needed
after the breaker failure logic unlatches (fault detectors 50P1 and 50N1 dropout).
Note that Figure SECTION 7: .25 suggests the option of having output contacts OUT103 and
OUT104 operate as additional breaker failure trip outputs. This is done by making the following
SEL
OGIC
Control Equation settings:
OUT103 = SV7T (breaker failure trip)
OUT104 = SV7T (breaker failure trip)
Settings Example 3
The seal-in logic circuit in the dedicated breaker failure scheme in Figure SECTION 7: .25 can
be removed by changing the SEL
OGIC
Control Equation setting SV7 to:
SV7 = IN101 * (50P1 + 50N1)
If the seal-in logic circuit is removed, optoisolated input IN101 (breaker failure initiate) has to be
continually asserted for a breaker failure time-out.
Timers Reset When Power is Lost, Settings are Changed, or Active Setting Group is
Changed
If power is lost to the relay, settings are changed (for the active setting group), or the active
setting group is changed, the SEL
OGIC
Control Equation variables/timers are reset. Relay Word
bits SVn and SVnT (n = 1 through 16) are reset to logical 0 and corresponding timer settings
SVnPU and SVnDO load up again after power restoration, settings change, or active setting
group switch.
Preceding Figure SECTION 7: .25 shows an effective seal-in logic circuit, created by use of
Relay Word bit SV7 (SEL
OGIC
Control Equation variable SV7) in SEL
OGIC
Control Equation
SV7:
SV7 = (SV7 + IN101) * (50P1 + 50N1)
If power is lost to the relay, settings are changed (for the active setting group), or the active
setting group is changed, the seal-in logic circuit is “broken” by virtue of Relay Word bit SV7
being reset to logical 0 (assuming input IN101 is not asserted). Relay Word bit SV7T is also
reset to logical 0, and timer settings SV7PU and SV7DO load up again.