Distance protection Relays
These phase and ground distance and directional protection relays can be applied for single- and three-pole tripping schemes, compensated lines, or uncompensated lines.
SEL-T401L
Ultra-High-Speed Line Relay
The SEL-T401L is a high-performance, easy-to-use line protective relay in a 3U package. Built on the field experience of the SEL-T400L Time-Domain Line Protection, the SEL-T401L delivers unprecedented operating times and includes the complete suite of primary and backup protection functions that you expect in a line protection system. Suitable for a wide range of applications, the SEL-T401L offers an opportunity to reset the complexity of line protection applications with its simple protection philosophies, and reduced settings count.
You can apply the SEL-T401L on its own or as part of a redundant protection system with other SEL relays without concerns for common-mode failures. The new technology of traveling waves and incremental quantities along with the enhancements and simplifications in phasor-based protection elements make the SEL-T401L protection philosophy, hardware, and software different from other SEL line protective relays. You’ll gain efficiency by using common SEL configuration and integration tools and also benefit from strong diversity in hardware, software, and protection operating principles.
SEL-421
Protection, Automation, and Control System
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. Optional Time-Domain Link (TiDL) technology and SEL Sampled Values (SV) technology using IEC 61850-9-2 transform the way you modernize your substation.
SEL-311C
Transmission Protection System
Apply the SEL-311C Relay for protection, reclosing, monitoring, and control of transmission lines.
Features include a four-shot recloser, patented capacitance voltage transformer (CVT) transient overreach logic to enhance security of Zone 1 distance elements, and overcurrent elements with directional control, monitoring, and metering. Apply three-pole tripping logic, or select the SEL-311C-3 for single-pole tripping. The SEL-311C comes standard with EIA-232 serial ports as well as a 10/100 BASE-T Ethernet port for local/remote access and system integration. IEEE C37.118 compliant synchrophasors are included for improved situational awareness.
SEL-321
Phase and Ground Distance Relay
The SEL-321 Relay delivers outstanding extra-high-voltage (EHV) protection, performance, and features-at a price practical for all voltage levels and with the features you need for system integration.
Apply the SEL-321 Relay for primary and/or backup single-or three-pole trip transmission line protection, including series-compensated lines.
Use the advanced single-pole tripping logic with phase selection, open-pole interval protection, and phase discordance logic with three-pole trip to protect against excessive single-pole-open events.
Choose from among the many communications-assisted tripping schemes available (POTT, DCUB, DCB, PUTT, DUTT, and DTT), including unique Mirrored Bits communications.
SEL -321-5
Phase and Ground Distance Relay
The SEL-321-5 Relay is designed especially for EHV and HV applications on 50 Hz systems. The relay provides enhanced single-pole tripping, phase and ground distance, directional overcurrent, negative-sequence overcurrent, and fault locating. The SEL-321-5 Relay contains all the protective elements and control logic necessary to protect, monitor, and control overhead lines.
Apply the SEL-321 Relay for primary and/or backup single-or three-pole trip transmission line protection, including series-compensated lines.
Use the advanced single-pole tripping logic with phase selection, open-pole interval protection, and phase discordance logic with three-pole trip to protect against excessive single-pole-open events.
Differential Protection Relays
The sensitive differential elements in these protective relays provide subcycle operating times and can be applied on multiterminal lines.
SEL-411L
Advanced Line Differential Protection, Automation, and Control System
Apply the SEL-411L for complete protection and control of any transmission line (short, long, or series-compensated). The SEL-411L provides differential protection with both phase- and sequence-based operating elements for sensitivity and high-speed operation. You can choose from many popular fiber and multiplexed communications options. Distance protection and logic from a complete SEL-421 Protection, Automation, and Control System are included to provide redundant protection and integration. The SEL-411L includes a traveling-wave fault locating method to locate faults within a tower span. Implement optional Time-Domain Link (TiDL) technology and Sampled Values (SV) technology using IEC 61850-9-2 to transform the way you modernize your substation.
Line Current Differential Protection—Apply subcycle single- or three-pole line current differential protection with backup distance protection for transmission lines using serial or Ethernet for differential communications. Patented generalized Alpha Plane technology combined with overcurrent supervision, external fault detection, and disturbance detection logic enables the 87L function to operate with exceptional security and sensitivity. You can invert individual or grouped CT or PT polarities to account for field wiring or protection zone changes.
SEL-311L
Line Current Differential Protection and Automation System
Use the SEL-311L Line Current Differential Relay with integral four-zone distance backup for easy-to-apply, high-speed line protection.
Apply subcycle current differential protection with included four-zone distance and directional overcurrent backup. Use single or dual differential channels for reliability. Apply the SEL-311L on two- or three-terminal lines. Unique measuring elements provide coordination with tapped loads. Reduce total project construction and operation costs through integration of the included four-shot recloser and relay logic operators into your automation system.
Improve protection system reliability with continuous checks of communications quality, breaker wear, battery voltage, and relay health. Use the included LCD display in place of traditional panel meters.
SEL-387L
Line Current Differential Relay
Use SEL-387L Line Current Differential Relays for economical, easy-to-apply line protection
Line Current Differential Protection—Protect two-terminal transmission and subtransmission lines with the same ratio CTs on each end. Apply a 64 kbps digital communications channel for complete phase and ground fault protection with simple settings.
Simple Installation—Set the relay in minutes! Only label the relay and terminals, and provide a unique address for the transmit and receive communications. Connect single-mode optical fiber, 1300 nm and 1550 nm, for distances up to 120 km (74 mi) without a repeater. No additional transceivers are required.
Ultra-High-Speed Protection Relays
These ultra-high-speed transmission line relays built with the time-domain technology of traveling waves and incremental quantities are designed for speed, security, and ease of use.
SEL-T401L
Ultra-High-Speed Line Relay
The SEL-T401L is a high-performance, easy-to-use line protective relay in a 3U package. Built on the field experience of the SEL-T400L Time-Domain Line Protection, the SEL-T401L delivers unprecedented operating times and includes the complete suite of primary and backup protection functions that you expect in a line protection system. Suitable for a wide range of applications, the SEL-T401L offers an opportunity to reset the complexity of line protection applications with its simple protection philosophies, and reduced settings count.
You can apply the SEL-T401L on its own or as part of a redundant protection system with other SEL relays without concerns for common-mode failures. The new technology of traveling waves and incremental quantities along with the enhancements and simplifications in phasor-based protection elements make the SEL-T401L protection philosophy, hardware, and software different from other SEL line protective relays. You’ll gain efficiency by using common SEL configuration and integration tools and also benefit from strong diversity in hardware, software, and protection operating principles.
SEL-T400L
Time-Domain Line Protection
Apply the SEL-T400L Time-Domain Line Protection for ultra-high-speed protection of transmission lines. With the breakthrough time-domain technology of traveling waves and incremental quantities, the SEL-T400L trips securely in as fast as 1 ms. The relay records events with a 1 MHz sampling rate, locates faults to the nearest tower, and monitors the line for incipient faults, recurring faults, or incipient cable faults. Adding the SEL-T400L to your line protection system can dramatically reduce your fault-clearing time and let you achieve the many benefits associated with speed.
Ultra-High-Speed Tripping With Security—The SEL-T400L features a traveling-wave differential scheme (TW87) over a dedicated point-to-point fiber channel; an incremental-quantity distance element (TD21) and a POTT scheme with traveling-wave (TW32) and incremental-quantity (TD32) directional elements over a digital or an analog protection channel. You can achieve 1–5 ms trip times, depending on the channel, line length, and system conditions
Systems Components
Combining these components with line protection relays expands their functionality and simplifies testing.
SEL-2507
High-Speed Remote I/O Module
The SEL-2507 High-Speed Remote I/O Module has eight inputs and eight outputs with an optional fiber-optic communications port. Connect the SEL-2507 to the SEL-T400L Time-Domain Line Protection or another SEL-2507 at 115.2 kbps to provide ultra-high-speed remote I/O. Millisecond Mirrored Bits messages transmit every 500 microseconds in these configurations, a four-fold increase over previous remote I/O applications.
Protection and Monitoring—Add simple bus protection using contact inputs and outputs from existing relays. Provide secure pilot communications for existing two- and three-terminal line applications. Add local or remote trip- and close-coil monitoring capability.
SEL-T4287
Traveling-Wave Test System
The SEL-T4287 is a simple-to-use, compact, and economical secondary pulse injection test set for testing traveling-wave fault locators and line protective relays. Traveling-wave fault locators and protection elements and schemes measure sharp changes in their input currents and voltages with rise times as fast as 1 microsecond. The fault locators and relays respond to relative polarities and relative timing of these sharp signal changes. The SEL-T4287 generates output current signals with the short rise time, adequately slow decay, and nanosecond precision necessary for testing standalone traveling-wave fault locators, traveling-wave protective relays, and traveling-wave fault locators embedded in line protective relays.
- Testing single-ended, double-ended, and multi-ended traveling-wave fault locators based on either currents or voltages.
- Testing traveling-wave directional protection elements.
- Testing traveling-wave current differential schemes
