421#01
Price: $11,171.94 | Savings: $408.00
- Standard distance protection
- Single- or three-pole operations
- Comprehensive communications protocols, including IEC 61850 Edition 2.1
SEL-421
Protection, Automation, and Control System
Apply the SEL-421 for high-speed distance and directional protection and complete control of a two-breaker bay.Protect any transmission line using a combination of five zones of phase- and ground-distance and directional overcurrent elements. A graphical user interface system provides logic and application templates for typical line protection schemes. Patented coupling capacitor voltage transformer (CCVT) transient overreach logic enhances the security of Zone 1 distance elements. Best Choice Ground Directional Element logic optimizes directional element performance and eliminates many directional settings. Optional additional logic prevents Zone 1 overreach on series-compensated lines. Optional incremental components provide subcycle operation for application on critical lines requiring high-speed fault clearing.Transform the way you modernize your substation with optional Time-Domain Link (TiDL) technology or Sampled Values (SV)-based technology using IEC 61850-9-2 or IEC 61869-9.
Starting at
$9,800
Subcycle Distance Protection
Protect critical transmission lines with high-speed quadrilateral, mho distance, and directional elements. Optional subcycle distance elements and series compensation logic reduce operating times to improve system stability. You can invert individual or grouped CT or PT polarities to account for field wiring or protection zone changes.
Single- or Three-Pole Operation
Incorporate programmable single- and three-pole tripping and reclosing of one or two circuit breakers into an integrated substation control system. Provide complete bay control with synchronism and voltage checks from multiple sources.
Series-Compensated Transmission Lines
Detect faults beyond a series capacitor and prevent Zone 1 overreach on series-compensated lines using the optional logic in the SEL-421-5 Protection, Automation, and Control System.
Communications-Assisted Tripping Schemes
Configure protection for transmission lines without any need for external coordination devices. The SEL-421 includes settings for permissive overreaching transfer trip (POTT), two-channel permissive overreaching transfer trip (POTT2), phase-segregated permissive overreaching transfer trip (POTT3), directional comparison unblocking (DCUB), and directional comparison blocking (DCB) schemes.
Out-of-Step Blocking and Tripping
Select from either out-of-step blocking of distance elements or out-of-step tripping during power swings. The relay includes multizone elements and logic for detection of an out-of-step condition.
Dual CT Applications
Apply the SEL-421 with ring-bus, breaker-and-a-half, or other two-breaker schemes. Combine currents within the relay from two sets of CTs for protection functions, but keep them separately available for monitoring and station integration applications.
Thermal Overload Protection
Use the three independent IEC 60255-149 thermal elements to activate a control action, issue an alarm, or trip when equipment overheats as a result of adverse operating conditions. The SEL-2600 RTD Module can provide ambient temperature measurements.
Underfrequency Load Shedding
Operate six levels of frequency elements as either an underfrequency or an overfrequency element. The frequency elements are suited for applications such as underfrequency load shedding and restoration control systems.
Bay Control, Reclosing, and Breaker Failure Protection
Apply complete bay control, reclosing, and breaker failure protection for two breakers. Monitor circuit breaker performance, including average and last tripping time, compressor run time, and contact-interrupting duty.
Digital Secondary System Technologies
SEL TiDL and SV-based solutions replace copper with fiber to increase safety, improve reliability, and limit the impact of an electromagnetic pulse. Apply the SEL-421-7 TiDL relay with the SEL-TMU TiDL Merging Unit in the field to provide remote I/O and digitize analog signals. This simple point-to-point solution with a strong cybersecurity posture is easy to implement. Apply the IEC-compliant SEL-421-7 SV relay to receive SV data from a remote merging unit via a network, or apply it as an SV merging unit to publish data to SV relays in the control house. Improve system availability in SV applications with the Parallel Redundancy Protocol (PRP), the High-availability Seamless Redundancy Protocol (HSR), or seamless failover using a five-port Ethernet card.
Flexible Communications Options
Use small form-factor pluggable (SFP) transceivers on designated process bus, station bus, and engineering access ports in the five-port Ethernet card. Choose between single- and multimode communications options for increased flexibility. All ports support 100 Mbps SFP transceivers, and process bus ports also support 1 Gbps SFP transceivers.
SEL-421 Features
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- EIA-232 serial port is quick and convenient for system setup and local access.
- The display allows operators to control and view the status of disconnects and breakers.
- The user-selectable mimic screens show the system configuration in one-line diagram format.
- Easy-to-use keypad aids simple navigation.
- LEDs indicate custom alarms and provide fast and simple information to assist dispatchers and line crews with rapid power restoration.
- Programmable operator pushbuttons with user-configurable labels allow customization.
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- Choose from a vertical or horizontal, panel-mount or rack-mount chassis and different size options.
- High-current interrupting output contacts increase contact robustness and reliability.
- Use the three EIA-232 ports for Mirrored Bits communications, DNP3, SCADA, and engineering access.
- Communications protocols include FTP, Telnet, synchrophasors, DNP3 LAN/WAN, PRP, IEC 61850 Edition 2.1 (optional feature), and the IEEE 1588 Precision Time Protocol Version 2 (PTPv2).
- Six current and six voltage analog inputs support complete bay control and protection as well as two-breaker bay applications.
- Power supply options include 24–48 Vdc; 48–125 Vdc or 110–120 Vac; or 125–250 Vdc or 110–240 Vac.
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- 4U chassis with mounting options (vertical or horizontal; panel or rack) accommodates your application needs.
- LEDs indicate the connection status to an SEL-TMU on a per-port basis.
- Eight SFP ports allow the TiDL relay to connect with eight remote SEL-TMU devices and to receive remote analog and digital data.
- Select a five-port Ethernet communications card for dedicated station bus and engineering access ports.
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- The 4U chassis has various mounting options to accommodate users’ hardware needs.
- Select a five-port Ethernet communications card for dedicated process bus, station bus, and engineering access ports.
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- Chassis options (for up to three I/O boards) and mounting options accommodate hardware needs.
- Select a five-port Ethernet card for dedicated process bus, station bus, and engineering access ports.
- Six current and six voltage analog inputs support signal digitization and local protection schemes.