Date Code 20020501
User’s Guide
SEL-421/SEL-421-1 Relay
Section 1
UUser’s Guide
Introduction and Specifications
The SEL-421 Relay is a high-speed transmission line protection relay
featuring single-pole and three-pole tripping and reclosing with synchronism
check, circuit breaker monitoring, circuit breaker failure protection, and
series-compensated line protection logic. The SEL-421-1 Relay contains all of
the protection functions of the SEL-421 Relay except high-speed distance
elements and series-compensated line protection logic. Both relays feature
extensive metering and data recording including high-resolution data capture
and reporting.
The relays feature expanded SEL
OGIC®
control equation programming for
easy and flexible implementation of custom protection and control schemes.
The SEL-421 Relay has separate protection and automation SEL
OGIC
control
equation programming areas with extensive protection programming
capability and 1000 lines of automation programming capability. You can
organize automation SEL
OGIC
control equation programming into 10 blocks
of 100 program lines each. The SEL-421-1 Relay has the same protection
programming capability but has only 1 block of 100 lines of automation
programming capability.
Both the SEL-421 Relay and the SEL-421-1 Relay provide extensive
communications interfaces from standard SEL ASCII and enhanced
M
IRRORED
B
ITS™
communications protocols to Ethernet connectivity with
the optional SEL-2701 Ethernet Processor. Using the SEL-421 Relay, you can
employ the latest industry communications tools including UCA2, FTP, and
DNP 3.0 protocols.
Included with the SEL-421 Relay and the SEL-421-1 Relay is the SEL-5030
AC
SEL
ERATOR®
Software Program. The
AC
SEL
ERATOR
software assists you
in setting, controlling, and acquiring data from the relays both locally and
remotely.
A simple and robust hardware design features efficient digital signal
processing. Combined with extensive self-testing, these features provide relay
reliability and enhance relay availability.
This section introduces the SEL-421 Relay and the SEL-421-1 Relay and
provides information on the following topics:
➤
Features
➤
Models and options
➤
Applications
➤
Specifications
Summary of Contents for SEL-421
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