Schweitzer Engineering Laboratories SEL-700G Series, Instruction Manual

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GL.2
SEL-700G Relay Instruction Manual Date Code 20170814
Glossary
ASCII — Dropout Time
ASCII Abbreviation for American Standard Code for Information Interchange.
Defines a standard way to communicate text characters between two elec-
tronic devices. The SEL-700G Generator and Intertie Protection Relay uses
ASCII text characters to communicate using the relay front- and rear-panel
EIA-232 serial ports.
Autosynchronism,
Autosynchronization
Function that checks the generator frequency and voltage and issues RAISE or
LOWER commands to the speed governor and the excitation system to bring
the generator frequency and voltage within tight bands and order the breaker
to close and complete the process of connecting the generator to the power
system when a generator is starting up.
Assert To activate; to fulfill the logic or electrical requirements necessary to operate a
device. To apply a short-circuit or closed contact to an SEL-700G input. To set
a logic condition to the true state (logical 1). To close a normally-open output
contact. To open a normally-closed output contact.
Breaker
Auxiliary Contact
A spare electrical contact associated with a circuit breaker that opens or closes
to indicate the breaker position. A form-a breaker auxiliary contact (ANSI
Standard Device Number 52A) closes when the breaker is closed, opens when
the breaker is open. A form-b breaker auxiliary contact (ANSI Standard
Device Number 52B) opens when the breaker is closed and closes when the
breaker is open.
Checksum A numeric identifier of the firmware in the relay. Calculated by the result of a
mathematic sum of the relay code.
CID Abbreviation for Checksum Identifier. The checksum of the specific firmware
installed in the relay.
Contiguous Items in sequence; the second immediately following the first.
CR_RAM Abbreviation for Critical RAM. Refers to the area of relay Random Access
Memory (RAM) where the relay stores mission-critical data.
CRC-16
Abbreviation for Cyclical Redundancy Check-16. A mathematical algorithm
applied to a block of digital information to produce a unique, identifying num-
ber. Used to ensure that the information was received without data corruption.
CT Abbreviation for current transformer.
Deassert To deactivate; to remove the logic or electrical requirements necessary to
operate a device. To remove a short-circuit or closed contact from an
SEL-700G input. To clear a logic condition to the false state (logical 0). To
open a normally-open output contact. To close a normally-closed output
contact.
Delta A phase-to-phase connection of voltage transformers for electrical measuring
purposes. Typically, two voltage transformers are used with one primary lead
of the first transformer connected to A-phase and the other lead connected to
B-phase. The second voltage transformer is connected to measure the voltage
from B-phase to C-phase. When two transformers are used, this connection is
frequently called “Open-Delta.”
Dropout Time The time measured from the removal of an input signal until the output signal
deasserts. The time can be settable, as in the case of a logic variable timer, or
can be a result of the characteristics of an element algorithm, as in the case of
an overcurrent element dropout time.