Schweitzer Engineering Laboratories SEL-351-5, Instruction Manual

Page: 17 / 706

Date Code 20070117
Instruction Manual SEL-351-5, -6, -7 Relay
Preface
UInstruction Manual
Manual Overview
The SEL-351-5, -6, -7 Instruction Manual describes common aspects of
protection relay application and use. It includes the necessary information to
install, set, test, and operate the relay and more detailed information about
settings and commands.
An overview of each manual section and topics follows:
Preface.
Describes the manual organization and conventions used to
present information.
Section 1: Introduction and Specifications.
Describes the basic features
and functions of the SEL-351; lists the relay specifications.
Section 2: Installation.
Describes how to mount and wire the SEL-351;
illustrates wiring connections for various applications; describes
operation of current board jumpers; and depicts relay front and rear
panels.
Section 3: Overcurrent, Voltage, Synchronism Check, Frequency, and
Power Elements.
Describes the operation of the instantaneous/definite-
time overcurrent elements (phase, neutral ground, residual ground, and
negative sequence); time-overcurrent elements (phase, neutral ground,
residual ground, and negative sequence); voltage elements (single
phase, phase to phase, etc.; synchronism check elements; frequency
elements; power elements (in Firmware Version 7); and voltage sag/
swell/interruption elements (in Firmware Version 7).
Section 4: Loss-of-Potential, Load Encroachment, and Directional Element
Logic.
Describes the operation of loss-of-potential logic and its effect on
directional elements; load-encroachment logic and its application to
phase overcurrent elements; voltage-polarized and current-polarized
directional elements, including directional control for low-impedance
grounded, Petersen Coil-grounded, and ungrounded/high-impedance
grounded systems; Best Choice Ground Directional
™
logic and
automatic settings.
Section 5: Trip and Target Logic.
Describes the operation of general trip
logic, switch-onto-fault trip logic, communications-assisted trip logic,
and front-panel target LEDs. Most tripping applications (not requiring
switch-onto-fault or communications-assisted tripping) require only
SEL
OGIC®
control equation trip setting TR and unlatch trip setting
ULTR in the general trip logic (see Figure 5.1 ).
Section 6: Close and Reclose Logic.
Describes the close logic operation
for automatic reclosures and other close conditions (e.g., manual close
initiation via serial port or optoisolated inputs).
Section 7: Inputs, Outputs, Timers, and Other Control Logic.
Describes the
operation of optoisolated inputs
IN101
–
IN106
(models 0351 x 0, 0351 x 1,
and 0351 x Y) and
IN201
–
IN208
(models 0351 x 1 and 0351 x Y), local
control switches (local bit outputs LB1–LB16), remote control
switches (remote bit outputs RB1–RB16), latch control switches (latch
bit outputs LT1–LT16), multiple setting groups (six available),