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SEL-421 Relay
Instruction Manual
Date Code 20171021
Preface
Safety Information
Section 19: Remote Data Acquisition
.
Describes the basic concepts of remote
data acquisition systems. This includes both the Time-Domain Link
(TiDL) remote data acquisition system, which uses SEL-2440 Axion
modules to provide remote data acquisition and I/O communication, and
UCA 61850-9-2LE Sampled Values.
.
Lists the current manual version and details dif-
ferences between the current and previous versions.
Appendix B: Firmware Upgrade Instructions
Describes the procedure to update
the firmware stored in Flash memory.
Appendix C: Cybersecurity Features
.
Describes the various features of the relay
that impact cybersecurity.
.
Definitions of various technical terms used in the SEL-400 series
instruction manuals.
Safety Information
Dangers, Warnings, and Cautions
This manual uses three kinds of hazard statements, defined as follows:
Safety Symbols
The following symbols are often marked on SEL products.
DANGER
Indicates an imminently hazardous situation that, if
not avoided,
will
result in death or serious injury.
WARNING
Indicates a potentially hazardous situation that, if
not avoided,
could
result in death or serious injury.
CAUTION
Indicates a potentially hazardous situation that, if
not avoided,
may
result in minor or moderate injury
or equipment damage.
CAUTION
Refer to accompanying documents.
ATTENTION
Se reporter à la documentation.
Earth (ground)
Terre
Protective earth (ground)
Terre de protection
Direct current
Courant continu
Alternating current
Courant alternatif
Both direct and alternating current
Courant continu et alternatif
Instruction manual
Manuel d’instructions
Summary of Contents for SEL-421-4
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