Sel 421 - Page 46

U.1.4
SEL-421 Relay User’s Guide Date Code 20090715
Introduction and Specifications
Features
Digital Relay-to-Relay Communication. Enhanced MIRRORED BITS
communications to monitor internal element conditions between
relays within a station, or between stations, using SEL fiber-optic
transceivers. Send digital, analog, and virtual terminal data over the
same M
IRRORED BITS channel.
Ethernet Access. Access all relay functions with the optional Ethernet
card. Interconnect with automation systems using IEC 61850 or DNP3
LAN/WAN protocols directly or DNP3 through an SEL-2032
Communications Processor. Use file transfer protocol (FTP) for high-
speed data collection.
Increased Security. The SEL-421 divides control and settings into seven
relay access levels; the relay has separate breaker, protection,
automation, and output access levels, among others. Set unique
passwords for each access level.
Rules-Based Settings Editor. Communicate with and set the relay using an
ASCII terminal, or use the PC-based
ACSELERATOR QuickSet
SEL-5030 Software to configure the SEL-421 and analyze fault
records with relay element response. View real-time phasors.
Settings Reduction. Internal relay programming shows only the settings
for the functions and elements you have enabled.
Thermal Overload Modeling. Use the SEL-421 with the SEL-2600A RTD
Module for dynamic overload protection using SEL
OGIC control
equations. For more information, see SEL Application Guide
AG2003-06, Implementation of the SEL-49 Relay Line Thermal
Protection Using the SEL-421 Relay SEL
OGIC Equations.
Alias Settings. Use as many as 200 aliases to rename any digital or analog
quantity in the relay. The aliases are now available for use in
customized programming, making the initial programming and
maintenance much easier.
Auxiliary {TRIP}/{CLOSE} Pushbuttons. The part number indicates whether
the relay has auxiliary {TRIP} and {CLOSE} pushbuttons. These
pushbuttons are shown in Figure 5.2. These features are electrically
isolated from the rest of the relay. They function independently from
the relay and do not need relay power.
Part numbers 0421xxxxxxxxxx3Axxxxx, 0421xxxxxxxxxx7Axxxxx,
0421xxxxxxxxxx3Bxxxxx, and 0421xxxxxxxxxx7Bxxxxx designate
relays with the auxiliary {TRIP} and {CLOSE} pushbuttons.
The lowercase xs in the above part numbers represent fields that
contain other values that are not important in determining the operator
controls of the relay. Refer to the SEL-421 Model Option Table for
complete part number details. These tables are available on the SEL
website or from the factory.
Courtesy of NationalSwitchgear.com