GL.14
SEL-400 Series Relays Instruction Manual Date Code 20171006
Glossary
Input Conditioning—Logical 1
Input Conditioning
The establishment of debounce time and assertion level.
Instance
A subdivision of a relay settings class. Group settings have several subdivisions
(Group 1–Group 6), while the Global settings class has one instance.
Instantaneous Meter
Type of meter data presented by the relay that includes the present values
measured at the relay ac inputs. The word “Instantaneous” is used to differentiate
these values from the measurements presented by the demand, thermal, energy,
and other meter types.
Internal Fuse
Fuse inside a capacitor unit.
IP Address
An identifier for a computer or device on a TCP/IP network. Networks using the
TCP/IP protocol route messages based on the IP address of the destination. The
format of an IP address is a 32-bit numeric address written as four numbers
separated by periods. Each number can be zero to 255. For example,
1.160.10.240 could be an IP address.
IRIG-B
A time code input that the relay can use to set the internal relay clock.
ISO 8802-3
Defines Ethernet for local area and metropolitan area networks.
Jitter
Time, amplitude, frequency, or phase-related abrupt, spurious variations in
duration, magnitude, or frequency.
L/R
Circuit inductive/resistive ratio.
LAN
Local Area Network. A network of IEDs interconnected in a relatively small
area, such as a room, building, or group of buildings.
Latch Bits
Nonvolatile storage locations for binary information.
LED
Light-emitting diode. Used as indicators on the relay front panel.
Left-Side Value
LVALUE. Result storage location of a SELOGIC control equation.
Line Impedance
The phasor sum of resistance and reactance in the form of positive-sequence,
negative-sequence, and zero-sequence impedances of the protected line.
LMD
SEL distributed port switch protocol.
LN Operator
Math SELOGIC control equation operator that provides natural logarithm.
Load Encroachment
The load-encroachment feature allows setting of phase overcurrent elements and
phase-distance elements independent of load levels.
Local Bits
The Relay Word bit outputs of local control switches that you access through the
front panel of the relay. Local control switches replace traditional panel-mounted
control switches.
Lockout Relay
An auxiliary relay that prevents operation of associated devices until it is reset
either electrically or by hand.
Logical 0
A false logic condition, dropped out element, or deasserted control input or
control output.
Logical 1
A true logic condition, picked up element, or asserted control input or control
output.
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