Schweitzer Engineering SEL-387-0 - Additional Relay Settings

6.3
Date Code 20170601 Instruction Manual SEL-387-0, -5, -6 Relay
Setting the Relay
Additional Relay Settings
Additional Relay Settings
The following explanations are for settings that are not discussed in earlier
sections.
Relay (RID) and
Terminal (TID)
Identification
The Relay Identifier (RID) and Terminal Identifier (TID) settings typically are
used to identify the equipment protected by the relay or the identifier of the
circuit breaker(s) controlled by the relay. The relay tags event reports with the
Relay and Terminal Identifier Strings. This allows you to distinguish the event
report as one generated for a specific breaker and substation. The RID setting
is limited to 39 characters and the TID setting to 59 characters. For our
example, we have selected RID = XFMR1 and TID = STATION A.
Demand Ammeter
Settings (DATC,
PDEM, QDEM, NDEM)
The relay provides demand ammeters for Windings 1 through 4, for phase,
negative-sequence, and residual currents. The relay saves time- and date-
stamped peak demand readings for each of the quantities. View this
information using the relay front panel or serial port METER commands.
The demand ammeters behave much like low-pass filters, responding to
gradual trends in the current magnitude. The relay uses the demand ammeter
time constant setting, DATCn, for all 5 demand ammeter calculations for
Winding “n.” The time constant is settable from 5 to 255 minutes. The demand
ammeters operate such that if demand current is reset and a constant input
current is applied, the demand current output will be 90 percent of the
constant input current value DATCn minutes later.
Settable demand ammeter thresholds are available for all five demand
ammeters in units of amps secondary. The thresholds are PDEMnP, QDEMnP,
and NDEMnP for the phase (A, B, and C), negative-sequence, and residual
demand ammeters, for Winding “n.” If demand currents exceed the set
threshold, the respective Relay Word bit PDEMn, QDEMn, or NDEMn
asserts. You can use these Relay Word bits to alarm for phase overload and
negative-sequence or residual current unbalance, for Winding “n.” See
Section 5: Metering and Monitoring for more information.
For our example, the Demand Ammeter function is enabled only for
Winding 1, the 230 kV primary winding, with the following settings:
DATC1 = 15 minutes, PDEM1P = 7 A, QDEM1P = 1 A, and NDEM1P = 1 A.
The demand ammeter settings can be different in the six settings groups.
Instantaneous metering functions have no settings. These functions show
primary phase, negative-sequence, and residual current magnitudes;
secondary winding current magnitudes and angles; differential quantities
(operate, restraint, second- and fifth-harmonics) in multiples of tap. Access is
by the front panel or one of the communications ports.
Input and Output
Assignments
Optoisolated inputs (IN101 through IN106) and contact outputs (OUT101 through
OUT107) are fully programmable, with no numbered input or output
specifically dedicated to a function. The one exception is the ALARM contact,
factory-set as a form-B contact (normally closed), and dedicated to the alarm
function. OUT107 can be made into an additional alarm contact that follows the
normal ALARM contact via JMP23 on the main board (see Section 2:
Installation). Standard SEL
OGIC
®
control equations can be written to drive the
output contacts. The inputs appear as elements of SEL
OGIC control equations.
Examples of this are illustrated in Trip and Close Logic on page 6.4. These
settings can be different in the six settings groups.