Sel 411L - Table 3.123 Additional Settings for Single-Pole Tripping (SPT); Trip Logic

P.3.237
Date Code 20151029 Protection Manual SEL-411L Relay
Protection Functions
Trip Logic
Trip Logic
Use the relay trip logic to configure the relay for tripping one or two circuit
breakers. You can apply the relay in single-pole tripping applications, three-
pole tripping applications, or both. Set the relay to trip from the 87L elements;
to trip unconditionally (as with step distance), or trip with the aid of a
communications channel (as with the POTT, DCUB, DCB, and DTT
schemes).
Three-Pole Tripping
The relay uses three-pole tripping logic if Relay Word bit E3PT (three-pole
trip enable SEL
OGIC control equation) equals logical 1. You can set E3PT to 1
or assign a control input so that an external condition changes the state of this
Relay Word bit.
The relay will also three-pole trip if a stub bus condition is asserted (see Stub
Bus Condition for more details) and the relay detects a fault within the stub
bus zone. Note that the 87OP Relay Word bit must be added to the TR,
unconditional tripping, equation in order to trip for an 87L element assertion.
There are separate three-pole tripping SEL
OGIC control equations for two
circuit breakers, E3PT1 and E3PT2, respectively. When you set E3PT1 or
E3PT2 to 1, the corresponding circuit breaker trips three pole only. For details
on setting E3PT, E3PT1, and E3PT2, see Trip Logic and Reclose Sources on
page P.4.9.
Single-Pole Tripping
The relay uses single-pole tripping logic if Relay Word bit E3PT, three-pole
trip enable SEL
OGIC control equation, equals logical 0. You can either set
E3PT to 0 or assign a control input so that an external condition changes the
state of this Relay Word bit.
The relay automatically single-pole trips for the following conditions when
the single-pole tripping logic is active.
➤ 87L phase element protection asserts for a single phase-to-
ground fault (note that the 87OP Relay Word bit needs to be
added to the TR, unconditional trip, equation to trip on an 87L
element assertion).
➤ Zone 1 ground distance protection asserts for a single phase-to-
ground fault.
➤ Zone 2 ground distance protection asserts for a single phase-to-
ground fault and is permitted to trip via the communications-
assisted tripping logic.
➤ Any one of three SELOGIC control equations, DTA, DTB, or
DTC, is assigned to an input and asserts (per-phase direct
transfer trip).
You can also set the relay to single-pole trip through the three options shown
in Table 3.123.
Table 3.123 Additional Settings for Single-Pole Tripping (SPT) (Sheet 1 of 2)
Setting Description Selection
E87DTT Enable 87 direct transfer trip receive SELOGIC Equation
Z2GTSP Zone 2 ground distance time delay single-pole trip Y
67QGSP Zone 2 directional negative-sequence/residual
ground overcurrent single-pole trip
Y