SEL-751AFEEDER PROTECTION RELAY

2

1 Copper or Fiber-Optic*Optional Feature

ANSI NUMBERS/ACRONYMS AND FUNCTIONS 25 Synchronism Check*27 Undervoltage*32 Directional Power50 Adaptive Overcurrent50 (P,G,Q) Overcurrent (Phase, Ground, Neg. Seq.)50N Neutral Overcurrent50N AF Arc-Flash Neutral Overcurrent*50P AF Arc-Flash Phase Overcurrent*51 (P,G,Q) Time-Overcurrent (Phase, Ground, Neg. Seq.)51N Neutral Time-Overcurrent52PB Trip/Close Pushbuttons55 Power Factor59 Overvoltage*79 Autoreclosing*81 (O,U,R/R,F) Over-/Underfrequency (Rate, Fast Rate)*85 RIO SEL Mirrored Bits® CommunicationsAFD Arc-Flash Detector*BRM Breaker Wear MonitorDFR Event ReportsLOP Loss-of-Potential Logic*

ADDITIONAL FUNCTIONSHMI Operator InterfaceLDP Load Data ProfilingLGC SELogic® Control EquationsPMU SynchrophasorsRTD TemperatureRTU Remote Terminal UnitSBM Station Battery Monitor*SER Sequential Events Recorder

Bus

Line

4

EIA-232EIA-485

2

Ethernet1

1

IRIG-B

1

1

1

3

3

2551N50N

27

27

3255

59

LOP

79

50PAF

50NAF

52PB

59PGQ

50PGQ

RF81O

UR

51PGQ

85RIO

AFD

BRM DFR RTD HMI LGC LDP MET

PMU SBMRTU SER

SEL-751A

52

Breaker

CBCTMeasured residual current IG*

FEEDER OVERCURRENT PROTECTION WITH OPTIONAL ARC-FLASH DETECTION

3

KEY FEATURESFeeder Protection

Protect radial and looped distribution circuits with comprehensive protection capabilities, including time-overcurrent, directional overcurrent, autoreclosing, over-/undervoltage, frequency, and much more.

Arc-Flash Mitigation

Improve safety for personnel with optional arc-flash detection capabilities. The SEL-751A Feeder Protection Relay offers combined light and high-speed overcurrent detection for arc-flash events. This combination provides the ideal solution for speed and security.

Automation and Control

Apply the SEL-751A on feeders to provide protection, automation, and control capabilities, all in one package. SELogic control equations support many automated applications without the need for additional automation controllers. The configurable front-panel buttons can replace conventional panel controls and simplify overall applications and wiring.

Event Analysis

Conduct postevent analysis more efficiently with the detailed event records that are available in the SEL-751A. Combine oscillographic and digital information to find root cause. Add a satellite-synchronized time source, like the SEL-2401 or SEL-2407® Satellite-Synchronized Clocks, for convenient alignment of event information from multiple devices.

Situational Awareness

Improve situational awareness and asset utilization with IEEE C37.118 synchrophasor measurement. Aggregate synchrophasor information from across your system to understand system trends, make decisions based on state measurement rather than state estimation, and aid in postevent analysis.

Reliable in Harsh Environments

Rely on the SEL-751A for protection and control applications, even in harsh and hazardous environments. The SEL-751A is designed and tested to meet and exceed utility and industrial requirements. An operating temperature range of –40° to +85°C (–40° to +185°F), Class 1, Division 2 approval, and optional conformal coating mean this relay will provide years of reliable service.

4

COORDINATE PROTECTION

Use SEL Mirrored Bits communications to coordinate upstream protection if a fault occurs. Coordination and fast-bus trip schemes allow short delays (two or three cycles) for backup protection, reducing arc-flash energy.

STAY OUTSIDE THE DANGER ZONE

Use Ethernet or serial communications to remotely obtain metering, event, and maintenance information from the relay. Optional delayed breaker tripping or closing via pushbuttons allows personnel to move to a safe distance.

Combine light-sensing technology with fast overcurrent protection to provide high-speed arc-flash detection without false tripping.

Fast and secure arc-flash protection reduces the incident energy of arc-flash events. The best way to avoid the dangers of arc flash is to stay out of the danger zone. SEL-751A Relays have integration and communications features for secure remote access to help you keep out of the danger zone while gathering important real-time and historical data from the relays. Coordinate protection for faster clearing times, and stay outside the danger zone completely with wireless or remote communications.

If you must be in the danger zone, know the dangers and wear appropriate personal protective equipment. If you do not know the arc-flash ratings and zones for your gear, SEL Engineering Services provides professional arc-flash hazard studies and practical approaches to mitigate arc-flash risks.

Bare-fiber sensors detect light from the arc flash over the entire length of the fiber loop. This type of sensor is used for large areas, such as busbars.

Easily mounted point sensors detect light from the arc flash in confined areas.

SEL-

751A

FaultCurrent

Arc-Flash Overcurrent

Arc-Flash Light Sensors(Up to Four)

Arc Flash

REDUCE ARC-FLASH HAZARDS

MIRRORED BITS®

Communications

Relay

Relay

Flash Protection

Prohibited Restricted

Limited

5

Front-panel LEDs can be programmed to indicate custom alarms.

User-configurable label kit included with relay.*

Large 2 x 16 character LCD.

Use default messages, or program up to 32 custom display messages.

Use default pushbuttons, or program your own pushbutton actions and labels.

Optional copper or fiber-optic Ethernet, Modbus® TCP, DNP3, or IEC 61850.

Power supply options include 24/48 Vdc, 125/250 Vdc, and 120/240 Vac.

Positions for optional I/O cards and voltage input card.

PRODUCT OVERVIEW

Optional arc-flash detection card and sensors.

FLEXIBLE COMMUNICATIONS

Communications Media Communications Protocols

Ethernet 10/100BASE-T Mirrored Bits communications

Ethernet 100BASE-FX IEC 61850

Single or dual Ethernet ports Modbus RTU/TCP

EIA-232 serial DNP3 serial, LAN/WAN

EIA-485 serial DeviceNet™

Fiber-optic, serial multimode ST® connectors Telnet

FTP

Synchrophasors (IEEE C37.118)

*User-configurable labels are an ordering option.

1

2

3

4

1

2

3

4

5

5

6

67

7

8

89

9

6

APPLICATIONS

FEEDER PROTECTIONProvide comprehensive protection capabilities, including time-overcurrent, definite-time overcurrent, over-/undervoltage, autoreclosing, frequency, and much more.ABC

Distribution Bus

Utility Distribution Feeder Protection and Reclosing 52

Trip andClose

SEL-

751A

ARC-FLASH MITIGATIONImprove safety and prevent damage with arc-flash detection in the SEL-751A. Choose from point sensors, loop sensors, or a combination to protect a wide variety of switchgear configurations.

Optical Arc-FlashDetector

LED Circuit forContinuousSelf-Testing

Point Sensor (SEL-C804) Application

Diffuser

Switc

hgea

r

Clear-Jacketed Fiber Black-Jacketed Fibers

Black-Jacketed Fibers

ST® Connector

V-P

in T

erm

inat

ions

SEL-751A

ARC

ARC

Clear-Jacketed Fiber Sensor (SEL-C804) Application

Ch. 2

Ch. 3

Ch. 4

Ch. 1

TM3

Core-BalanceCurrent Transformer

Trip

NAB

C

SEL-

751A

52

INDUSTRIAL FEEDER PROTECTIONProvide overcurrent, voltage, and frequency protection for industrial and commercial feeders. Apply a core balance current transformer (CT) to detect ground faults and to provide an added level of protection.

7

EASY TO SET AND USEUSE ACSELERATOR QUICKSET® SEL-5030 SOFTWARE TO SET, MONITOR, AND CONTROL THE SEL-751A

· Save engineering time while keeping flexibility. Communicate with the SEL-751A through any ASCII terminal, or use the acseLerator QuickSet graphical user interface.

· Develop settings offline with a menu-driven interface and completely documented help screens. Speed installation by copying existing settings files and modifying application-specific items.

· Simplify the setting procedure with rule-based architecture to automatically check interrelated settings. Out-of-range or conflicting settings are highlighted for correction.

USE ACSELERATOR® SOFTWARE TO RETRIEVE AND DISPLAY EVENT REPORTS RECORDED BY THE SEL-751A

· Display event report oscillograms. View each report as a plot of magnitude versus time. Select analog and digital points to build a custom display. Analyze arc-flash events using light intensity and phase current waveforms recorded during the arc fault.

· Display phase and symmetrical component phasors. Display the phasor view of electrical data to better understand asymmetrical three-phase faults. Build a custom plot using per-phase and symmetrical component sequence currents and voltages.

· Retrieve event reports using serial or Ethernet communications links.

Phase current

Light intensity

Operate times as fast as 2 ms

Fault-clearing time

5.0 7.5Cycles

10.0

© 2007–2014 by Schweitzer Engineering Laboratories, Inc. PF00154 · 20140911

SCHWEITZER ENGINEERING LABORATORIES, INC.

Tel: +1.509.332.1890 Email: info@selinc.com Web: www.selinc.com

MAKING ELECTRIC POWER SAFER, MORE RELIABLE, AND MORE ECONOMICAL

MOUNTING AND ENCLOSURE OPTIONSMount the SEL-751A into multiple locations using our complete line of mounting and enclosure options. Choose from panel-mount, rack-mount, wall-mount, indoor, or outdoor configurations.

Panel-Mounting Kits

Replace existing feeder protection with the SEL-751A and the applicable mounting kit. These kits provide everything needed to replace many existing feeder relays with the SEL-751A.

19-Inch Rack-Mounting Kits

Use a 19-inch rack-mounting kit to easily install the SEL-751A and other SEL-700 series relays into 19-inch racks. A variety of kits are available for one or two relays, or to mount a relay with an FT-1 test switch (not included).

Wall-Mounting, Indoor, and Outdoor Enclosure Kits

Choose one of the optional kits to install the SEL-751A and other SEL-700 series relays into a variety of configurations.

Visit www.selinc.com/mounting_selector to see the complete selection of mounting and enclosure kits. No cutting or drilling is required when you use the optional

mounting kits. Replacement of existing protection is quick and easy!