GE UR Series L90, Instruction Manual, Page: 395 / 846

GE Multilin L90 Line Current Differential System 5-257
5 SETTINGS 5.7 CONTROL ELEMENTS
5
• TRIP MODE : This setting is used to select the required mode of operation. If selected to “3 Pole Only” outputs for all
three phases are always set simultaneously. If selected to “3 Pole & 1 Pole” outputs for all three phases are set simul-
taneously unless the phase selector or a pilot aided scheme determines the fault is single-phase-to-ground. If the fault
is identified as being AG, BG or CG only the operands for the faulted phase will be asserted.
• TRIP 3-POLE INPUT-1 to TRIP 3-POLE INPUT-6 : These settings are used to select an operand representing a fault
condition that is not desired to initiate a single pole operation (for example, phase undervoltage). Use a FlexLogic OR-
gate if more than six inputs are required.
• TRIP 1-POLE INPUT-1 to TRIP 1-POLE INPUT-6 : These settings are used to select an operand representing a fault
condition that is desired to initiate a single pole trip-and-reclose if the fault is single phase to ground (for example, dis-
tance zone 1). Use a FlexLogic OR-gate if more than six inputs are required. The inputs do not have to be phase-spe-
cific as the phase selector determines the fault type.
The
AR FORCE 3-P TRIP
operand is asserted by the autorecloser 1.5 cycles after single-pole reclosing is initiated. This
operand calls for a three-pole trip if any protection element configured under
TRIP 1-POLE INPUT
remains picked-up. The
open pole detector provides blocking inputs to distance elements, and therefore the latter will reset immediately after
the
TRIP 1-POLE
operand is asserted. For other protection elements used in single-pole tripping, the user must ensure
they will reset immediately after tripping, otherwise the fact that they are still picked up will be detected as an evolving
fault and the relay will trip three-poles. For example, if high-set phase instantaneous overcurrent is used (
TRIP 1-POLE
INPUT X:
“
PHASE IOC1 OP
”), then
OPEN POLE OP

A
shall be used for blocking phase A of the instantaneous overcur-
rent element. In this way, after tripping phase A, the phase a instantaneous overcurrent element is forced to reset.
Phases B and C are still operational and can detect an evolving fault as soon as 8 ms after tripping phase A. Neutral
and negative-sequence instantaneous overcurrent elements shall be blocked from the
OPEN POLE BLK N
operand
unless the pickup setting is high enough to prevent pickup during single-pole reclosing.
• TRIP RECLOSE INPUT-1 to TRIP RECLOSE INPUT-6 : These settings select an operand representing a fault condi-
tion that is desired to initiate three pole reclosing (for example, phase distance zone 1). Use a FlexLogic OR-gate if
more than six inputs are required. These inputs also include the
TRIP 1-POLE INPUT-1
to
TRIP 1-POLE INPUT-6
values,
which are intended to initiate three-pole reclosing in situations where single-pole tripping commands are changed to
three-pole tripping commands. This can happen in cases where the phase selector identifies a multi-phase fault or the
AR FORCE 3P TRIP
command is present.
• TRIP SEAL-IN DELAY : This setting specifies the minimum time that trip command signals are maintained to provide
sufficient time to open the breaker poles. If a value of “0” is specified, then the output signal is reset once the protection
elements initiating the trip are reset. If a value other than “0” is specified, then the protection elements must reset and
the timer initiated at the first trip command must expire.
• TRIP RESET : This setting selects the option to reset the trip latches. If “Pole Curr OR Custom” is chosen, then the
OPEN POLE CURRENT PKP
setting should be programmed accordingly. If “CBaux OR Custom” is chosen, then the break-
ers should be set appropriately. Both the “Current” and “CBaux” options can be complimented by custom conditions
using the
BKR Φ A OPEN
,
BKR Φ B OPEN
, and
BKR Φ C OPEN
settings indicated below. Alternately, a purely custom condi-
tion can be applied to reset trip output latches.
• START TMR Z2PH Inp1 and START TMR Z2PH Inp2 : These settings select an operand that will start the phase dis-
tance zone 2 timer to avoid a trip delay if the fault evolves from one type to another type (for example, from a single-
line–to-ground fault to a multi-phase fault) or from one zone of protection to another zone of protection (for example,
from zone 3 to zone 2). For instance, the
GND DIST Z2 PKP
FlexLogic operand or the
PH DIST Z3 PKP
FlexLogic oper-
and could be assigned to either of these settings. Use a FlexLogic OR-gate if more than two inputs are required. Refer
to phase distance logic diagrams for additional information.
• START TMR Z2GR Inp1 and START TMR Z2GR Inp2 : These settings select an operand that will start the ground dis-
tance zone 2 timer to avoid a trip delay if the fault evolves from one zone of protection to another zone of protection (for
example, from zone 3 to zone 2). For instance, the
GND DIST Z3 PKP
FlexLogic operand could be assigned to these
settings. Use a FlexLogic OR-gate if more than two inputs are required. Refer to ground distance logic diagrams for
additional information.
• BKR Φ A OPEN , BKR Φ B OPEN , and BKR Φ C OPEN : This settings are used to select an operand to indicates that
phase A, B, or C of the breaker is open, respectively.
• TRIP FORCE 3-POLE : Selects an operand that will force an input selected for single pole operation to produce a three
pole operation. The
AR DISABLED
FlexLogic operand is the recommended value for this setting. Power system config-
urations or conditions which require such operations may be considered as well.